diff --git a/README b/README
index 5b36747c2..99e19b4d6 100644
--- a/README
+++ b/README
@@ -106,7 +106,7 @@ how to set up PostgreSQL. On debian, the two packages needed are:
 
 For other operating systems, please refer to the relevant documentation.
 
-In this settlement, the exchange wll use a database called 'talercheck' and will
+In this settlement, the exchange will use a database called 'talercheck' and will
 run under the username through which 'taler-exchange-httpd' is launched. Thus assuming
 that this user is 'demo', we need to create a 'demo' role for postgresql and make
 him the owner of 'talercheck' database.
diff --git a/contrib/auditor-report.tex.j2 b/contrib/auditor-report.tex.j2
index 4d01f2f51..5aade17da 100644
--- a/contrib/auditor-report.tex.j2
+++ b/contrib/auditor-report.tex.j2
@@ -468,7 +468,7 @@ the financial damage done to the customer).
 Note that the deltas only sum up the issues where $P \not= 0$ as only
 then we can tell if the problem lead to a profit or loss.
 
-The {\bf P} colum is set to "1" if the arithmetic problem was be determined to be
+The {\bf P} column is set to "1" if the arithmetic problem was be determined to be
 profitable for the exchange, "-1" if the problem resulted in a net loss for
 the exchange, and "0" if this is unclear or at least the gain/loss is not
 easily determined from the amounts and thus not included in the totals.
diff --git a/src/auditor/generate-auditor-basedb.sh b/src/auditor/generate-auditor-basedb.sh
index fa693b561..3ecd43dd0 100755
--- a/src/auditor/generate-auditor-basedb.sh
+++ b/src/auditor/generate-auditor-basedb.sh
@@ -31,7 +31,7 @@ BASEDB=${1:-"auditor-basedb"}
 # elsewhere
 TARGET_DB=taler-auditor-basedb
 
-# Configuation file will be edited, so we create one
+# Configuration file will be edited, so we create one
 # from the template.
 CONF=generate-auditor-basedb-prod.conf
 cp generate-auditor-basedb-template.conf $CONF
diff --git a/src/auditor/generate-revoke-basedb.sh b/src/auditor/generate-revoke-basedb.sh
index 2a24ad5fe..e687b1ffd 100755
--- a/src/auditor/generate-revoke-basedb.sh
+++ b/src/auditor/generate-revoke-basedb.sh
@@ -27,7 +27,7 @@ TMP_DIR=`mktemp -d revocation-tmp-XXXXXX`
 export WALLET_DB=wallet-revocation.json
 rm -f $WALLET_DB
 
-# Configuation file will be edited, so we create one
+# Configuration file will be edited, so we create one
 # from the template.
 export CONF=generate-auditor-basedb-revocation.conf
 cp generate-auditor-basedb-template.conf $CONF
diff --git a/src/auditor/taler-auditor-httpd.c b/src/auditor/taler-auditor-httpd.c
index c84327045..4f7e11f84 100644
--- a/src/auditor/taler-auditor-httpd.c
+++ b/src/auditor/taler-auditor-httpd.c
@@ -125,7 +125,7 @@ handle_signal (int signal_number)
                   1);
   /* While one might like to "handle errors" here, even logging via fprintf()
      isn't safe inside of a signal handler. So there is nothing we safely CAN
-     do. OTOH, also very little that can go wrong in pratice. Calling _exit()
+     do. OTOH, also very little that can go wrong in practice. Calling _exit()
      on errors might be a possibility, but that might do more harm than good. *///
 }
 
diff --git a/src/auditor/taler-helper-auditor-coins.c b/src/auditor/taler-helper-auditor-coins.c
index 24d490343..fb50c8dbf 100644
--- a/src/auditor/taler-helper-auditor-coins.c
+++ b/src/auditor/taler-helper-auditor-coins.c
@@ -1578,9 +1578,9 @@ refresh_session_cb (void *cls,
  * @param coin_sig signature from the coin
  * @param amount_with_fee amount that was deposited including fee
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param refund_deadline by which the merchant adviced that he might want
+ * @param refund_deadline by which the merchant advised that he might want
  *        to get a refund
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param receiver_wire_account wire details for the merchant, NULL from iterate_matching_deposits()
  * @param done flag set if the deposit was already executed (or not)
diff --git a/src/auditor/taler-helper-auditor-wire.c b/src/auditor/taler-helper-auditor-wire.c
index f074e5a1a..59cb544a4 100644
--- a/src/auditor/taler-helper-auditor-wire.c
+++ b/src/auditor/taler-helper-auditor-wire.c
@@ -222,18 +222,18 @@ static json_t *report_reserve_in_inconsistencies;
 static json_t *report_missattribution_in_inconsistencies;
 
 /**
- * Array of reports about row inconcistencies.
+ * Array of reports about row inconsistencies.
  */
 static json_t *report_row_inconsistencies;
 
 /**
- * Array of reports about inconcistencies in the database about
+ * Array of reports about inconsistencies in the database about
  * the incoming wire transfers (exchange is not exactly to blame).
  */
 static json_t *report_wire_format_inconsistencies;
 
 /**
- * Array of reports about minor row inconcistencies.
+ * Array of reports about minor row inconsistencies.
  */
 static json_t *report_row_minor_inconsistencies;
 
diff --git a/src/auditordb/auditor-0000.sql b/src/auditordb/auditor-0000.sql
index 1483e2015..116f409b7 100644
--- a/src/auditordb/auditor-0000.sql
+++ b/src/auditordb/auditor-0000.sql
@@ -150,7 +150,7 @@ BEGIN;
 -- It requires that PL/pgSQL is already loaded - will raise exception otherwise.
 -- All versioning "stuff" (tables, functions) is in "_v" schema.
 
--- All functions are defined as 'RETURNS SETOF INT4' to be able to make them to RETURN literaly nothing (0 rows).
+-- All functions are defined as 'RETURNS SETOF INT4' to be able to make them to RETURN literally nothing (0 rows).
 -- >> RETURNS VOID<< IS similar, but it still outputs "empty line" in psql when calling.
 CREATE SCHEMA IF NOT EXISTS _v;
 COMMENT ON SCHEMA _v IS 'Schema for versioning data and functionality.';
diff --git a/src/auditordb/plugin_auditordb_postgres.c b/src/auditordb/plugin_auditordb_postgres.c
index d48defb15..467c4c6db 100644
--- a/src/auditordb/plugin_auditordb_postgres.c
+++ b/src/auditordb/plugin_auditordb_postgres.c
@@ -3192,7 +3192,7 @@ libtaler_plugin_auditordb_postgres_init (void *cls)
   if (0 != pthread_key_create (&pg->db_conn_threadlocal,
                                &db_conn_destroy))
   {
-    TALER_LOG_ERROR ("Cannnot create pthread key.\n");
+    TALER_LOG_ERROR ("Cannot create pthread key.\n");
     GNUNET_free (pg);
     return NULL;
   }
diff --git a/src/bank-lib/bank_api_transfer.c b/src/bank-lib/bank_api_transfer.c
index c8fbe6908..0cf59602e 100644
--- a/src/bank-lib/bank_api_transfer.c
+++ b/src/bank-lib/bank_api_transfer.c
@@ -369,7 +369,7 @@ TALER_BANK_transfer (
  * succeed.
  *
  * The caller MUST run #TALER_BANK_transfer() again for the same request as
- * soon as possilbe, to ensure that the request either ultimately succeeds or
+ * soon as possible, to ensure that the request either ultimately succeeds or
  * ultimately fails. Until this has been done, the transaction is in limbo
  * (i.e. may or may not have been committed).
  *
diff --git a/src/bank-lib/fakebank.c b/src/bank-lib/fakebank.c
index 8f4a36102..9c4aeb6e9 100644
--- a/src/bank-lib/fakebank.c
+++ b/src/bank-lib/fakebank.c
@@ -867,7 +867,7 @@ struct HistoryArgs
  *
  * @param connection MHD connection.
  * @param[out] ha will contain the parsed values.
- * @return #GNUNET_OK only if the parsing succeedes.
+ * @return #GNUNET_OK only if the parsing succeeds.
  */
 static int
 parse_history_common_args (struct MHD_Connection *connection,
diff --git a/src/bank-lib/taler-bank-transfer.c b/src/bank-lib/taler-bank-transfer.c
index 4b2a06fc1..bc4ebcfbc 100644
--- a/src/bank-lib/taler-bank-transfer.c
+++ b/src/bank-lib/taler-bank-transfer.c
@@ -484,7 +484,7 @@ res_cb (void *cls,
     break;
   default:
     fprintf (stderr,
-             "Operation failed with staus code %u/%u\n",
+             "Operation failed with status code %u/%u\n",
              (unsigned int) ec,
              http_status);
     if (NULL != json)
diff --git a/src/benchmark/benchmark.conf b/src/benchmark/benchmark.conf
index bb1f17f83..b9d1d141d 100644
--- a/src/benchmark/benchmark.conf
+++ b/src/benchmark/benchmark.conf
@@ -1,7 +1,7 @@
 # This file is in the public domain.
 #
 [paths]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 # This value is a default for `taler_config_home'
 taler_test_home = exchange_benchmark_home/
 
@@ -69,7 +69,7 @@ enable_credit = YES
 
 
 [fees-x-taler-bank]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 wire-fee-2018 = EUR:0.01
 wire-fee-2019 = EUR:0.01
diff --git a/src/exchange-tools/taler-exchange-keyup.c b/src/exchange-tools/taler-exchange-keyup.c
index 544e9634f..f4d389752 100644
--- a/src/exchange-tools/taler-exchange-keyup.c
+++ b/src/exchange-tools/taler-exchange-keyup.c
@@ -235,7 +235,7 @@ static struct GNUNET_TIME_Relative max_duration_spend;
 static struct GNUNET_HashCode revoke_dkh;
 
 /**
- * Which RSA key size should we use for replacment keys after revocation?
+ * Which RSA key size should we use for replacement keys after revocation?
  * (Useful because maybe that's the one option one might usefully want to
  * change when replacing a key.)
  */
@@ -1151,7 +1151,7 @@ check_revocation_regeneration (
   if (now.abs_value_us >= withdraw_end.abs_value_us)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                "Revoked denomination key has expired, no need to create a replacment\n");
+                "Revoked denomination key has expired, no need to create a replacement\n");
     return GNUNET_NO;
   }
 
diff --git a/src/exchange-tools/test_taler_exchange_httpd.conf b/src/exchange-tools/test_taler_exchange_httpd.conf
index d6748b5d3..27fc067a9 100644
--- a/src/exchange-tools/test_taler_exchange_httpd.conf
+++ b/src/exchange-tools/test_taler_exchange_httpd.conf
@@ -1,5 +1,5 @@
 [PATHS]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 TALER_TEST_HOME = test_taler_exchange_httpd_home/
 
 [taler]
@@ -70,7 +70,7 @@ TALER_BANK_AUTH_METHOD = NONE
 
 # Wire fees are specified by wire method
 [fees-x-taler-bank]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2018, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
diff --git a/src/exchange/exchange.conf b/src/exchange/exchange.conf
index 9de198949..3abd8efd9 100644
--- a/src/exchange/exchange.conf
+++ b/src/exchange/exchange.conf
@@ -18,7 +18,7 @@ REVOCATION_DIR = ${TALER_DATA_HOME}/exchange/revocations/
 # How long do we allow /keys to be cached at most? The actual
 # limit is the minimum of this value and the first expected
 # significant change in /keys based on the expiration times.
-# Used to artifically reduce caching (addresses #5747).
+# Used to artificially reduce caching (addresses #5747).
 MAX_KEYS_CACHING = forever
 
 # After how many requests should the exchange auto-restart
diff --git a/src/exchange/taler-exchange-aggregator.c b/src/exchange/taler-exchange-aggregator.c
index 63a72c79e..da24a125d 100644
--- a/src/exchange/taler-exchange-aggregator.c
+++ b/src/exchange/taler-exchange-aggregator.c
@@ -156,7 +156,7 @@ static struct GNUNET_SCHEDULER_Task *task;
 static struct GNUNET_TIME_Relative aggregator_idle_sleep_interval;
 
 /**
- * Value to return from main(). 0 on success, non-zero on erorrs.
+ * Value to return from main(). 0 on success, non-zero on errors.
  */
 static enum
 {
@@ -193,7 +193,7 @@ run_aggregation (void *cls);
 /**
  * Free data stored in @a au, but not @a au itself (stack allocated).
  *
- * @param au aggreation unit to clean up
+ * @param au aggregation unit to clean up
  */
 static void
 cleanup_au (struct AggregationUnit *au)
@@ -335,7 +335,7 @@ refund_by_coin_cb (void *cls,
  * @param amount_with_fee amount that was deposited including fee
  * @param deposit_fee amount the exchange gets to keep as transaction fees
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param wire wire details for the merchant
  * @return transaction status code,  #GNUNET_DB_STATUS_SUCCESS_ONE_RESULT to continue to iterate
@@ -506,7 +506,7 @@ deposit_cb (void *cls,
  * @param amount_with_fee amount that was deposited including fee
  * @param deposit_fee amount the exchange gets to keep as transaction fees
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param wire wire details for the merchant
  * @return transaction status code
diff --git a/src/exchange/taler-exchange-httpd_keystate.c b/src/exchange/taler-exchange-httpd_keystate.c
index 1fee70e86..1c56b7a0f 100644
--- a/src/exchange/taler-exchange-httpd_keystate.c
+++ b/src/exchange/taler-exchange-httpd_keystate.c
@@ -476,7 +476,7 @@ handle_signal (int signal_number)
                   1);
   /* While one might like to "handle errors" here, even logging via fprintf()
      isn't safe inside of a signal handler. So there is nothing we safely CAN
-     do. OTOH, also very little that can go wrong in pratice. Calling _exit()
+     do. OTOH, also very little that can go wrong in practice. Calling _exit()
      on errors might be a possibility, but that might do more harm than good. *///
 }
 
@@ -489,7 +489,7 @@ handle_signal (int signal_number)
  *
  * @param pk public key of the denomination
  * @param dki the denomination key issue information
- * @return a JSON object describing the denomination key isue (public part)
+ * @return a JSON object describing the denomination key issue (public part)
  */
 static json_t *
 denom_key_issue_to_json (
@@ -560,7 +560,7 @@ store_in_map (struct GNUNET_CONTAINER_MultiHashMap *map,
               const struct TALER_EXCHANGEDB_DenominationKey *dki)
 {
   /* First, we verify that the @a dki is actually well-formed.  While it comes
-     from our own hard disk, there is the possibility of missconfiguration
+     from our own hard disk, there is the possibility of misconfiguration
      (i.e. bogus file in the directory), or that the administrator used the
      wrong master public key, and we should not accept entries that are not
      well-formed. *///
@@ -2554,7 +2554,7 @@ TEH_handler_keys (const struct TEH_RequestHandler *rh,
     if (NULL == key_state)
     {
       /* Maybe client picked time stamp too far in the future?  In that case,
-         #MHD_HTTP_INTERNAL_SERVER_ERROR might be missleading, could be more like a
+         #MHD_HTTP_INTERNAL_SERVER_ERROR might be misleading, could be more like a
          NOT_FOUND situation. But, OTOH, for 'sane' clients it is more likely
          to be our fault, so let's speculatively assume we are to blame ;-) */
       return TALER_MHD_reply_with_error (connection,
@@ -2584,7 +2584,7 @@ TEH_handler_keys (const struct TEH_RequestHandler *rh,
     if (NULL == krd)
     {
       /* Maybe client picked time stamp too far in the future?  In that case,
-         "INTERNAL_SERVER_ERROR" might be missleading, could be more like a
+         "INTERNAL_SERVER_ERROR" might be misleading, could be more like a
          NOT_FOUND situation. But, OTOH, for 'sane' clients it is more likely
          to be our fault, so let's speculatively assume we are to blame ;-) *///
       GNUNET_break (0);
diff --git a/src/exchange/taler-exchange-httpd_melt.c b/src/exchange/taler-exchange-httpd_melt.c
index c4c80c130..9bff205c2 100644
--- a/src/exchange/taler-exchange-httpd_melt.c
+++ b/src/exchange/taler-exchange-httpd_melt.c
@@ -90,7 +90,7 @@ reply_melt_insufficient_funds (
  * Send a response to a "melt" request.
  *
  * @param connection the connection to send the response to
- * @param rc value the client commited to
+ * @param rc value the client committed to
  * @param noreveal_index which index will the client not have to reveal
  * @return a MHD status code
  */
diff --git a/src/exchange/taler-exchange-httpd_refreshes_reveal.c b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
index 00b8592d3..7496de01f 100644
--- a/src/exchange/taler-exchange-httpd_refreshes_reveal.c
+++ b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
@@ -115,7 +115,7 @@ struct RevealContext
 {
 
   /**
-   * Commitment of the refresh operaton.
+   * Commitment of the refresh operation.
    */
   struct TALER_RefreshCommitmentP rc;
 
diff --git a/src/exchange/taler-exchange-httpd_responses.c b/src/exchange/taler-exchange-httpd_responses.c
index c3fcd5994..452841190 100644
--- a/src/exchange/taler-exchange-httpd_responses.c
+++ b/src/exchange/taler-exchange-httpd_responses.c
@@ -15,7 +15,7 @@
 */
 /**
  * @file taler-exchange-httpd_responses.c
- * @brief API for generating genric replies of the exchange; these
+ * @brief API for generating generic replies of the exchange; these
  *        functions are called TEH_RESPONSE_reply_ and they generate
  *        and queue MHD response objects for a given connection.
  * @author Florian Dold
diff --git a/src/exchange/taler-exchange-wirewatch.c b/src/exchange/taler-exchange-wirewatch.c
index ede6220ba..fba002970 100644
--- a/src/exchange/taler-exchange-wirewatch.c
+++ b/src/exchange/taler-exchange-wirewatch.c
@@ -634,7 +634,7 @@ main (int argc,
       GNUNET_PROGRAM_run (argc, argv,
                           "taler-exchange-wirewatch",
                           gettext_noop (
-                            "background process that watches for incomming wire transfers from customers"),
+                            "background process that watches for incoming wire transfers from customers"),
                           options,
                           &run, NULL))
   {
diff --git a/src/exchange/test_taler_exchange_unix.conf b/src/exchange/test_taler_exchange_unix.conf
index b9cc4b3d5..bc870d4bb 100644
--- a/src/exchange/test_taler_exchange_unix.conf
+++ b/src/exchange/test_taler_exchange_unix.conf
@@ -1,5 +1,5 @@
 [PATHS]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 TALER_TEST_HOME = test_taler_exchange_httpd_home/
 
 [taler]
@@ -74,7 +74,7 @@ TALER_BANK_AUTH_METHOD = NONE
 
 # Wire fees are specified by wire method
 [fees-x-taler-bank]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2018, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
diff --git a/src/exchangedb/exchange-0000.sql b/src/exchangedb/exchange-0000.sql
index 1483e2015..116f409b7 100644
--- a/src/exchangedb/exchange-0000.sql
+++ b/src/exchangedb/exchange-0000.sql
@@ -150,7 +150,7 @@ BEGIN;
 -- It requires that PL/pgSQL is already loaded - will raise exception otherwise.
 -- All versioning "stuff" (tables, functions) is in "_v" schema.
 
--- All functions are defined as 'RETURNS SETOF INT4' to be able to make them to RETURN literaly nothing (0 rows).
+-- All functions are defined as 'RETURNS SETOF INT4' to be able to make them to RETURN literally nothing (0 rows).
 -- >> RETURNS VOID<< IS similar, but it still outputs "empty line" in psql when calling.
 CREATE SCHEMA IF NOT EXISTS _v;
 COMMENT ON SCHEMA _v IS 'Schema for versioning data and functionality.';
diff --git a/src/exchangedb/exchangedb_accounts.c b/src/exchangedb/exchangedb_accounts.c
index db23eafca..b66b1bcc1 100644
--- a/src/exchangedb/exchangedb_accounts.c
+++ b/src/exchangedb/exchangedb_accounts.c
@@ -39,7 +39,7 @@ static struct TALER_EXCHANGEDB_WireAccount *wa_tail;
 struct FindAccountContext
 {
   /**
-   * Configuration we are usign.
+   * Configuration we are using.
    */
   const struct GNUNET_CONFIGURATION_Handle *cfg;
 
diff --git a/src/exchangedb/exchangedb_auditorkeys.c b/src/exchangedb/exchangedb_auditorkeys.c
index d285fc5e6..0a0370cfe 100644
--- a/src/exchangedb/exchangedb_auditorkeys.c
+++ b/src/exchangedb/exchangedb_auditorkeys.c
@@ -108,7 +108,7 @@ auditor_iter (void *cls,
                              GNUNET_YES))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                "Skipping inaccessable auditor information file `%s'\n",
+                "Skipping inaccessible auditor information file `%s'\n",
                 filename);
     return GNUNET_OK;
   }
diff --git a/src/exchangedb/exchangedb_denomkeys.c b/src/exchangedb/exchangedb_denomkeys.c
index 6c5465869..fe74d1560 100644
--- a/src/exchangedb/exchangedb_denomkeys.c
+++ b/src/exchangedb/exchangedb_denomkeys.c
@@ -124,7 +124,7 @@ TALER_EXCHANGEDB_denomination_key_read (
                              GNUNET_YES))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                "Skipping inaccessable denomination key file `%s'\n",
+                "Skipping inaccessible denomination key file `%s'\n",
                 filename);
     return GNUNET_SYSERR;
   }
diff --git a/src/exchangedb/plugin_exchangedb_postgres.c b/src/exchangedb/plugin_exchangedb_postgres.c
index c21f1b1a9..a639b133d 100644
--- a/src/exchangedb/plugin_exchangedb_postgres.c
+++ b/src/exchangedb/plugin_exchangedb_postgres.c
@@ -2570,7 +2570,7 @@ postgres_get_reserve_history (void *cls,
  * @param cls the `struct PostgresClosure` with the plugin-specific state
  * @param session database connection
  * @param deposit deposit to search for
- * @param check_extras wether to check extra fields match or not
+ * @param check_extras whether to check extra fields match or not
  * @return 1 if we know this operation,
  *         0 if this exact deposit is unknown to us,
  *         otherwise transaction error status
@@ -7226,7 +7226,7 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
   if (0 != pthread_key_create (&pg->db_conn_threadlocal,
                                &db_conn_destroy))
   {
-    TALER_LOG_ERROR ("Cannnot create pthread key.\n");
+    TALER_LOG_ERROR ("Cannot create pthread key.\n");
     GNUNET_free (pg->sql_dir);
     GNUNET_free (pg);
     return NULL;
diff --git a/src/exchangedb/test_exchangedb.c b/src/exchangedb/test_exchangedb.c
index ba8059c4d..a92721641 100644
--- a/src/exchangedb/test_exchangedb.c
+++ b/src/exchangedb/test_exchangedb.c
@@ -838,7 +838,7 @@ static uint64_t deposit_rowid;
  * @param amount_with_fee amount that was deposited including fee
  * @param deposit_fee amount the exchange gets to keep as transaction fees
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param wire wire details for the merchant, NULL from iterate_matching_deposits()
  * @return transaction status code, #GNUNET_DB_STATUS_SUCCESS_ONE_RESULT to continue to iterate
@@ -897,9 +897,9 @@ deposit_cb (void *cls,
  * @param coin_sig signature from the coin
  * @param amount_with_fee amount that was deposited including fee
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param refund_deadline by which the merchant adviced that he might want
+ * @param refund_deadline by which the merchant advised that he might want
  *        to get a refund
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param receiver_wire_account wire details for the merchant, NULL from iterate_matching_deposits()
  * @param done flag set if the deposit was already executed (or not)
@@ -1785,7 +1785,7 @@ run (void *cls)
       FAILIF (0 != memcmp (&bt->reserve_pub,
                            &reserve_pub,
                            sizeof (reserve_pub)));
-      /* this is the amount we trasferred twice*/
+      /* this is the amount we transferred twice*/
       FAILIF (1 != bt->amount.value);
       FAILIF (1000 != bt->amount.fraction);
       FAILIF (0 != strcmp (CURRENCY, bt->amount.currency));
diff --git a/src/include/taler_amount_lib.h b/src/include/taler_amount_lib.h
index f088d89b4..3da2b851e 100644
--- a/src/include/taler_amount_lib.h
+++ b/src/include/taler_amount_lib.h
@@ -34,7 +34,7 @@ extern "C"
  * @brief Number of characters (plus 1 for 0-termination) we use to
  * represent currency names (i.e. EUR, USD, etc.).  We use 8+4 for
  * alignment in the `struct TALER_Amount`.  The amount is typically an
- * ISO 4217 currency code when an alpha-numeric 3-digit code is used.
+ * ISO 4217 currency code when an alphanumeric 3-digit code is used.
  * For regional currencies, the first character should be a "*" followed
  * by a region-specific name (i.e. "*BRETAGNEFR").
  */
diff --git a/src/include/taler_bank_service.h b/src/include/taler_bank_service.h
index 44487a61a..0212e61f1 100644
--- a/src/include/taler_bank_service.h
+++ b/src/include/taler_bank_service.h
@@ -232,7 +232,7 @@ TALER_BANK_transfer (struct GNUNET_CURL_Context *ctx,
  * succeed.
  *
  * The caller MUST run #TALER_BANK_transfer() again for the same request as
- * soon as possilbe, to ensure that the request either ultimately succeeds or
+ * soon as possible, to ensure that the request either ultimately succeeds or
  * ultimately fails. Until this has been done, the transaction is in limbo
  * (i.e. may or may not have been committed).
  *
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index 57f02054d..868bbebe9 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -398,7 +398,7 @@ struct TALER_TrackTransferDetails
  * @param denom_pub denomination key, must match @a coin_public_info's `denom_pub_hash`
  * @return #GNUNET_YES if the coin is valid,
  *         #GNUNET_NO if it is invalid
- *         #GNUNET_SYSERR if an internal error occured
+ *         #GNUNET_SYSERR if an internal error occurred
  */
 int
 TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info,
diff --git a/src/include/taler_error_codes.h b/src/include/taler_error_codes.h
index ff3cb7a5c..626f9a9f8 100644
--- a/src/include/taler_error_codes.h
+++ b/src/include/taler_error_codes.h
@@ -1086,20 +1086,20 @@ enum TALER_ErrorCode
   TALER_EC_RECOUP_REPLY_MALFORMED = 1861,
 
   /**
-   * The "have" parameter was not a natural number. This reponse is
+   * The "have" parameter was not a natural number. This response is
    * provied with an HTTP status code of #MHD_HTTP_BAD_REQUEST.
    */
   TALER_EC_KEYS_HAVE_NOT_NUMERIC = 1900,
 
   /**
-   * We currently cannot find any keys. This reponse is provied with an
+   * We currently cannot find any keys. This response is provied with an
    * HTTP status code of #MHD_HTTP_INTERNAL_SERVER_ERROR.
    */
   TALER_EC_KEYS_MISSING = 1901,
 
   /**
    * This exchange does not allow clients to request /keys for times
-   * other than the current (exchange) time. This reponse is provied
+   * other than the current (exchange) time. This response is provied
    * with an HTTP status code of #MHD_HTTP_FORBIDDEN.
    */
   TALER_EC_KEYS_TIMETRAVEL_FORBIDDEN = 1902,
@@ -1295,7 +1295,7 @@ enum TALER_ErrorCode
   TALER_EC_PAY_WRONG_INSTANCE = 2127,
 
   /**
-   * Integer overflow with sepcified timestamp argument detected. This
+   * Integer overflow with specified timestamp argument detected. This
    * response is provided with HTTP status code #MHD_HTTP_BAD_REQUEST.
    */
   TALER_EC_HISTORY_TIMESTAMP_OVERFLOW = 2200,
@@ -1836,7 +1836,7 @@ enum TALER_ErrorCode
   TALER_EC_SERVER_SIGNATURE_INVALID = 5001,
 
   /**
-   * Wire tranfer attempted with credit and debit party being the same
+   * Wire transfer attempted with credit and debit party being the same
    * bank account.
    */
   TALER_EC_BANK_SAME_ACCOUNT = 5102,
diff --git a/src/include/taler_exchangedb_plugin.h b/src/include/taler_exchangedb_plugin.h
index c19428b18..4fd580724 100644
--- a/src/include/taler_exchangedb_plugin.h
+++ b/src/include/taler_exchangedb_plugin.h
@@ -243,7 +243,7 @@ struct TALER_EXCHANGEDB_CollectableBlindcoin
   struct TALER_Amount amount_with_fee;
 
   /**
-   * Withdrawl fee charged by the exchange.  This must match the Exchange's
+   * Withdrawal fee charged by the exchange.  This must match the Exchange's
    * denomination key's withdrawal fee.  If the client puts in an
    * invalid withdrawal fee (too high or too low) that does not match
    * the Exchange's denomination key, the withdraw operation is invalid
@@ -441,7 +441,7 @@ struct TALER_EXCHANGEDB_ReserveHistory
   struct TALER_EXCHANGEDB_ReserveHistory *next;
 
   /**
-   * Type of the event, determins @e details.
+   * Type of the event, determines @e details.
    */
   enum TALER_EXCHANGEDB_ReserveOperation type;
 
@@ -980,7 +980,7 @@ struct TALER_EXCHANGEDB_Session;
  * @param amount_with_fee amount that was deposited including fee
  * @param deposit_fee amount the exchange gets to keep as transaction fees
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param receiver_wire_account wire details for the merchant, includes
  *        'url' in payto://-format; NULL from iterate_matching_deposits()
@@ -1029,9 +1029,9 @@ typedef void
  * @param coin_sig signature from the coin
  * @param amount_with_fee amount that was deposited including fee
  * @param h_contract_terms hash of the proposal data known to merchant and customer
- * @param refund_deadline by which the merchant adviced that he might want
+ * @param refund_deadline by which the merchant advised that he might want
  *        to get a refund
- * @param wire_deadline by which the merchant adviced that he would like the
+ * @param wire_deadline by which the merchant advised that he would like the
  *        wire transfer to be executed
  * @param receiver_wire_account wire details for the merchant including 'url' in payto://-format;
  *        NULL from iterate_matching_deposits()
@@ -1840,7 +1840,7 @@ struct TALER_EXCHANGEDB_Plugin
    * @param cls the @e cls of this struct with the plugin-specific state
    * @param session database connection
    * @param deposit deposit to search for
-   * @param check_extras wether to check extra fields or not
+   * @param check_extras whether to check extra fields or not
    * @return 1 if we know this operation,
    *         0 if this exact deposit is unknown to us,
    *         otherwise transaction error status
diff --git a/src/include/taler_signatures.h b/src/include/taler_signatures.h
index 17a8ed86b..e8fc57ded 100644
--- a/src/include/taler_signatures.h
+++ b/src/include/taler_signatures.h
@@ -322,7 +322,7 @@ struct TALER_WithdrawRequestPS
   struct TALER_AmountNBO amount_with_fee;
 
   /**
-   * Withdrawl fee charged by the exchange.  This must match the Exchange's
+   * Withdrawal fee charged by the exchange.  This must match the Exchange's
    * denomination key's withdrawal fee.  If the client puts in an
    * invalid withdrawal fee (too high or too low) that does not match
    * the Exchange's denomination key, the withdraw operation is invalid
diff --git a/src/include/taler_testing_lib.h b/src/include/taler_testing_lib.h
index 78e5edfd5..c8949ee38 100644
--- a/src/include/taler_testing_lib.h
+++ b/src/include/taler_testing_lib.h
@@ -295,7 +295,7 @@ struct TALER_TESTING_BankConfiguration
 
 /**
  * Prepare launching a fakebank.  Check that the configuration
- * file has the right option, and that the port is avaiable.
+ * file has the right option, and that the port is available.
  * If everything is OK, return the configuration data of the fakebank.
  *
  * @param config_filename configuration file to use
@@ -1605,7 +1605,7 @@ TALER_TESTING_cmd_check_bank_transfer_with_ref (const char *label,
 
 
 /**
- * Checks wheter all the wire transfers got "checked"
+ * Checks whether all the wire transfers got "checked"
  * by the "bank check" CMD.
  *
  * @param label command label.
@@ -1727,7 +1727,7 @@ TALER_TESTING_cmd_sleep (const char *label,
 
 /**
  * This CMD simply tries to connect via HTTP to the
- * service addressed by @a url.  It attemps 10 times
+ * service addressed by @a url.  It attempts 10 times
  * before giving up and make the test fail.
  *
  * @param label label for the command.
diff --git a/src/lib/exchange_api_handle.c b/src/lib/exchange_api_handle.c
index 67df86bdb..cb02f68e0 100644
--- a/src/lib/exchange_api_handle.c
+++ b/src/lib/exchange_api_handle.c
@@ -783,7 +783,7 @@ denoms_cmp (struct TALER_EXCHANGE_DenomPublicKey *denom1,
 
   denom1->key.rsa_public_key = NULL;
   denom2->key.rsa_public_key = NULL;
-  /* Then procede with the rest of the object.  */
+  /* Then proceed with the rest of the object.  */
   ret = GNUNET_memcmp (denom1,
                        denom2);
   denom1->revoked = r1;
diff --git a/src/lib/exchange_api_refreshes_reveal.c b/src/lib/exchange_api_refreshes_reveal.c
index 5d186cd32..f07dc9047 100644
--- a/src/lib/exchange_api_refreshes_reveal.c
+++ b/src/lib/exchange_api_refreshes_reveal.c
@@ -95,7 +95,7 @@ struct TALER_EXCHANGE_RefreshesRevealHandle
  *
  * @param rrh operation handle
  * @param json reply from the exchange
- * @param[out] sigs array of length `num_fresh_coins`, initialized to cointain RSA signatures
+ * @param[out] sigs array of length `num_fresh_coins`, initialized to contain RSA signatures
  * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
  */
 static int
@@ -248,7 +248,7 @@ handle_refresh_reveal_finished (void *cls,
     ec = TALER_JSON_get_error_code (j);
     break;
   case MHD_HTTP_CONFLICT:
-    /* Nothing really to verify, exchange says our reveal is inconsitent
+    /* Nothing really to verify, exchange says our reveal is inconsistent
        with our commitment, so either side is buggy; we
        should pass the JSON reply to the application */
     ec = TALER_JSON_get_error_code (j);
diff --git a/src/testing/test-taler-exchange-aggregator-postgres.conf b/src/testing/test-taler-exchange-aggregator-postgres.conf
index f7da395d4..d4252e23f 100644
--- a/src/testing/test-taler-exchange-aggregator-postgres.conf
+++ b/src/testing/test-taler-exchange-aggregator-postgres.conf
@@ -1,5 +1,5 @@
 [PATHS]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 TALER_TEST_HOME = test_taler_exchange_httpd_home/
 
 [taler]
@@ -73,7 +73,7 @@ HTTP_PORT = 8082
 
 [fees-x-taler-bank]
 
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2018, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
diff --git a/src/testing/test-taler-exchange-wirewatch-postgres.conf b/src/testing/test-taler-exchange-wirewatch-postgres.conf
index 67696e583..420a46f1d 100644
--- a/src/testing/test-taler-exchange-wirewatch-postgres.conf
+++ b/src/testing/test-taler-exchange-wirewatch-postgres.conf
@@ -1,5 +1,5 @@
 [PATHS]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 TALER_TEST_HOME = test_taler_exchange_httpd_home/
 
 [taler]
@@ -65,7 +65,7 @@ HTTP_PORT = 8082
 
 [fees-x-taler-bank]
 
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2018, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
diff --git a/src/testing/test_auditor_api.c b/src/testing/test_auditor_api.c
index be1654c69..7b6996264 100644
--- a/src/testing/test_auditor_api.c
+++ b/src/testing/test_auditor_api.c
@@ -411,7 +411,7 @@ run (void *cls,
                                        MHD_HTTP_OK),
     /**
      * These commands should close the reserve because the aggregator
-     * is given a config file that ovverrides the reserve expiration
+     * is given a config file that overrides the reserve expiration
      * time (making it now-ish)
      */CMD_TRANSFER_TO_EXCHANGE ("short-lived-reserve",
                               "EUR:5.01"),
diff --git a/src/testing/test_auditor_api.conf b/src/testing/test_auditor_api.conf
index c43e1ad49..890812c55 100644
--- a/src/testing/test_auditor_api.conf
+++ b/src/testing/test_auditor_api.conf
@@ -2,7 +2,7 @@
 # This file is in the public domain.
 #
 [PATHS]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 TALER_TEST_HOME = test_exchange_api_home/
 
 [taler]
@@ -93,7 +93,7 @@ ENABLE_CREDIT = YES
 # Sections starting with "fee-" configure the wire fee for the
 # respective wire method.
 [fees-iban]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
@@ -118,7 +118,7 @@ CLOSING-FEE-2026 = EUR:0.01
 CLOSING-FEE-2027 = EUR:0.01
 
 [fees-x-taler-bank]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
diff --git a/src/testing/test_exchange_api.c b/src/testing/test_exchange_api.c
index 4c56925dd..0c3f48379 100644
--- a/src/testing/test_exchange_api.c
+++ b/src/testing/test_exchange_api.c
@@ -201,7 +201,7 @@ run (void *cls,
      * is currently the case because of the "timestamp" field,
      * which is set automatically by #TALER_TESTING_cmd_deposit().
      * This could theoretically fail if at some point a deposit
-     * command executs in less than 1 ms. *///
+     * command executes in less than 1 ms. *///
     TALER_TESTING_cmd_deposit ("deposit-double-1",
                                "withdraw-coin-1",
                                0,
@@ -676,7 +676,7 @@ run (void *cls,
                               "EUR:3.99",
                               MHD_HTTP_OK),
     /* These commands should close the reserve because
-     * the aggregator is given a config file that ovverrides
+     * the aggregator is given a config file that overrides
      * the reserve expiration time (making it now-ish) */
     CMD_TRANSFER_TO_EXCHANGE ("short-lived-reserve",
                               "EUR:5.01"),
diff --git a/src/testing/test_exchange_api.conf b/src/testing/test_exchange_api.conf
index 1b16444ff..07d0e6c03 100644
--- a/src/testing/test_exchange_api.conf
+++ b/src/testing/test_exchange_api.conf
@@ -2,7 +2,7 @@
 #
 
 [PATHS]
-# Persistant data storage for the testcase
+# Persistent data storage for the testcase
 TALER_TEST_HOME = test_exchange_api_home/
 
 
@@ -95,7 +95,7 @@ HTTP_PORT = 9081
 # Sections starting with "fee-" configure the wire fee for the
 # respective wire method.
 [fees-iban]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
@@ -120,7 +120,7 @@ CLOSING-FEE-2026 = EUR:0.01
 CLOSING-FEE-2027 = EUR:0.01
 
 [fees-x-taler-bank]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 WIRE-FEE-2018 = EUR:0.01
 WIRE-FEE-2019 = EUR:0.01
diff --git a/src/testing/test_exchange_api_keys_cherry_picking.conf b/src/testing/test_exchange_api_keys_cherry_picking.conf
index b67440d68..d81f2c96b 100644
--- a/src/testing/test_exchange_api_keys_cherry_picking.conf
+++ b/src/testing/test_exchange_api_keys_cherry_picking.conf
@@ -4,7 +4,7 @@
 # Persistent data storage for the testcase
 TALER_TEST_HOME = test_exchange_api_keys_cherry_picking_home/
 
-# Persistant data storage
+# Persistent data storage
 TALER_DATA_HOME = $TALER_HOME/.local/share/taler/
 
 # Configuration files
@@ -33,7 +33,7 @@ signkey_duration = 5 seconds
 # how long are the signatures with the signkey valid?
 legal_duration = 2 years
 
-# This vaule causes keys to be *RETURNED* in a /keys response.
+# This value causes keys to be *RETURNED* in a /keys response.
 # It's a relative time that materializes always in now+itsvalue.
 # We keep it very high, so as to not introduce divergencies between
 # keys that have been created and keys that are returned along /keys.
@@ -99,7 +99,7 @@ ENABLE_CREDIT = YES
 HTTP_PORT=8082
 
 [fees-x-taler-bank]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 WIRE-FEE-2017 = EUR:0.01
 WIRE-FEE-2018 = EUR:0.01
@@ -143,7 +143,7 @@ CLOSING-FEE-2035 = EUR:0.01
 
 
 [fees-iban]
-# Fees for the forseeable future...
+# Fees for the foreseeable future...
 # If you see this after 2017, update to match the next 10 years...
 WIRE-FEE-2017 = EUR:0.01
 WIRE-FEE-2018 = EUR:0.01
diff --git a/src/testing/testing_api_cmd_bank_check_empty.c b/src/testing/testing_api_cmd_bank_check_empty.c
index ee16e5a91..84976b0b5 100644
--- a/src/testing/testing_api_cmd_bank_check_empty.c
+++ b/src/testing/testing_api_cmd_bank_check_empty.c
@@ -89,7 +89,7 @@ check_bank_empty_traits (void *cls,
 
 
 /**
- * Checks wheter all the wire transfers got "checked"
+ * Checks whether all the wire transfers got "checked"
  * by the "bank check" CMD.
  *
  * @param label command label.
diff --git a/src/testing/testing_api_cmd_wait.c b/src/testing/testing_api_cmd_wait.c
index 919fb7c3b..40f4d360a 100644
--- a/src/testing/testing_api_cmd_wait.c
+++ b/src/testing/testing_api_cmd_wait.c
@@ -109,7 +109,7 @@ wait_service_run (void *cls,
 
 /**
  * This CMD simply tries to connect via HTTP to the
- * service addressed by @a url.  It attemps 10 times
+ * service addressed by @a url.  It attempts 10 times
  * before giving up and make the test fail.
  *
  * @param label label for the command.
diff --git a/src/testing/testing_api_helpers_exchange.c b/src/testing/testing_api_helpers_exchange.c
index d7195a9c4..872d23b9b 100644
--- a/src/testing/testing_api_helpers_exchange.c
+++ b/src/testing/testing_api_helpers_exchange.c
@@ -380,7 +380,7 @@ struct SignInfo
  * Sign the keys for an exchange given configuration @a cfg.
  * The information to be signed must be in a file "auditor.in".
  *
- * @param[in,out] cls a `struct SignInfo` with further paramters
+ * @param[in,out] cls a `struct SignInfo` with further parameters
  * @param cfg configuration to use
  * @return #GNUNET_OK on success
  */
diff --git a/src/testing/testing_api_loop.c b/src/testing/testing_api_loop.c
index 5bfb7fe0e..361fe6305 100644
--- a/src/testing/testing_api_loop.c
+++ b/src/testing/testing_api_loop.c
@@ -176,7 +176,7 @@ TALER_TESTING_interpreter_next (struct TALER_TESTING_Interpreter *is)
   struct TALER_TESTING_Command *cmd = &is->commands[is->ip];
 
   if (GNUNET_SYSERR == is->result)
-    return; /* ignore, we already failled! */
+    return; /* ignore, we already failed! */
   if (TALER_TESTING_cmd_is_batch (cmd))
   {
     TALER_TESTING_cmd_batch_next (is);
diff --git a/src/util/amount.c b/src/util/amount.c
index fb5a41d74..717144984 100644
--- a/src/util/amount.c
+++ b/src/util/amount.c
@@ -556,7 +556,7 @@ TALER_amount_normalize (struct TALER_Amount *amount)
  * Convert the fraction of @a amount to a string in decimals.
  *
  * @param amount value to convert
- * @param[out] tail where to write the reesult
+ * @param[out] tail where to write the result
  */
 static void
 amount_to_tail (const struct TALER_Amount *amount,
diff --git a/src/util/crypto.c b/src/util/crypto.c
index cbc5f2cb2..99171ebc7 100644
--- a/src/util/crypto.c
+++ b/src/util/crypto.c
@@ -77,7 +77,7 @@ TALER_gcrypt_init ()
  * @param denom_pub denomination key, must match @a coin_public_info's `denom_pub_hash`
  * @return #GNUNET_YES if the coin is valid,
  *         #GNUNET_NO if it is invalid
- *         #GNUNET_SYSERR if an internal error occured
+ *         #GNUNET_SYSERR if an internal error occurred
  */
 int
 TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info,
diff --git a/src/util/paths.conf b/src/util/paths.conf
index 03febb0e4..c1d2194d8 100644
--- a/src/util/paths.conf
+++ b/src/util/paths.conf
@@ -16,7 +16,7 @@ TALER_HOME = ${TALER_TEST_HOME:-${HOME:-${USERPROFILE}}}
 # http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
 # for how these should be used.
 
-# Persistant data storage
+# Persistent data storage
 TALER_DATA_HOME = ${XDG_DATA_HOME:-$TALER_HOME/.local/share}/taler/
 
 # Configuration files
diff --git a/src/util/url.c b/src/util/url.c
index ec94f58b3..d681fd02b 100644
--- a/src/util/url.c
+++ b/src/util/url.c
@@ -213,7 +213,7 @@ serialize_arguments (struct GNUNET_Buffer *buf,
  * @param ... NULL-terminated key-value pairs (char *) for query parameters,
  *        the value will be url-encoded
  * @returns the URL (must be freed with #GNUNET_free) or
- *          NULL if an error occured.
+ *          NULL if an error occurred.
  */
 char *
 TALER_url_join (const char *base_url,