diff --git a/contrib/bloom/blscan.c b/contrib/bloom/blscan.c
index 316a906734..11b7505e58 100644
--- a/contrib/bloom/blscan.c
+++ b/contrib/bloom/blscan.c
@@ -76,7 +76,7 @@ blendscan(IndexScanDesc scan)
 }
 
 /*
- * Insert all matching tuples into to a bitmap.
+ * Insert all matching tuples into a bitmap.
  */
 int64
 blgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index e9588a7f69..6c9cc1c538 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -2551,7 +2551,7 @@ SetOffsetVacuumLimit(void)
 
 	/*
 	 * NB: Have to prevent concurrent truncation, we might otherwise try to
-	 * lookup a oldestMulti that's concurrently getting truncated away.
+	 * lookup an oldestMulti that's concurrently getting truncated away.
 	 */
 	LWLockAcquire(MultiXactTruncationLock, LW_SHARED);
 
@@ -2727,7 +2727,7 @@ find_multixact_start(MultiXactId multi, MultiXactOffset *result)
 	/*
 	 * Flush out dirty data, so PhysicalPageExists can work correctly.
 	 * SimpleLruFlush() is a pretty big hammer for that.  Alternatively we
-	 * could add a in-memory version of page exists, but find_multixact_start
+	 * could add an in-memory version of page exists, but find_multixact_start
 	 * is called infrequently, and it doesn't seem bad to flush buffers to
 	 * disk before truncation.
 	 */
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 4053b5105d..865990b1a5 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1542,7 +1542,7 @@ finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap,
 	 * swap_relation_files()), thus relfrozenxid was not updated. That's
 	 * annoying because a potential reason for doing a VACUUM FULL is a
 	 * imminent or actual anti-wraparound shutdown.  So, now that we can
-	 * access the new relation using it's indices, update relfrozenxid.
+	 * access the new relation using its indices, update relfrozenxid.
 	 * pg_class doesn't have a toast relation, so we don't need to update the
 	 * corresponding toast relation. Not that there's little point moving all
 	 * relfrozenxid updates here since swap_relation_files() needs to write to
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 71ef9adf3b..c619347348 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -1067,7 +1067,7 @@ lreplace:;
  * (but still lock row, even though it may not satisfy estate's
  * snapshot).
  *
- * Returns true if if we're done (with or without an update), or false if
+ * Returns true if we're done (with or without an update), or false if
  * the caller must retry the INSERT from scratch.
  */
 static bool
diff --git a/src/backend/replication/logical/origin.c b/src/backend/replication/logical/origin.c
index c281734fd5..d6bae6cc89 100644
--- a/src/backend/replication/logical/origin.c
+++ b/src/backend/replication/logical/origin.c
@@ -1404,7 +1404,7 @@ pg_show_replication_origin_status(PG_FUNCTION_ARGS)
 	int			i;
 #define REPLICATION_ORIGIN_PROGRESS_COLS 4
 
-	/* we we want to return 0 rows if slot is set to zero */
+	/* we want to return 0 rows if slot is set to zero */
 	replorigin_check_prerequisites(false, true);
 
 	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
diff --git a/src/bin/initdb/t/001_initdb.pl b/src/bin/initdb/t/001_initdb.pl
index 372865d3f7..f1c14045c8 100644
--- a/src/bin/initdb/t/001_initdb.pl
+++ b/src/bin/initdb/t/001_initdb.pl
@@ -1,4 +1,4 @@
-# To test successful data directory creation with a additional feature, first
+# To test successful data directory creation with an additional feature, first
 # try to elaborate the "successful creation" test instead of adding a test.
 # Successful initdb consumes much time and I/O.
 
diff --git a/src/bin/pg_upgrade/tablespace.c b/src/bin/pg_upgrade/tablespace.c
index 8e09ec3729..68046a101b 100644
--- a/src/bin/pg_upgrade/tablespace.c
+++ b/src/bin/pg_upgrade/tablespace.c
@@ -36,7 +36,7 @@ init_tablespaces(void)
  * get_tablespace_paths()
  *
  * Scans pg_tablespace and returns a malloc'ed array of all tablespace
- * paths. Its the caller's responsibility to free the array.
+ * paths. It's the caller's responsibility to free the array.
  */
 static void
 get_tablespace_paths(void)
diff --git a/src/interfaces/ecpg/ecpglib/execute.c b/src/interfaces/ecpg/ecpglib/execute.c
index f74ed5e800..5b09233810 100644
--- a/src/interfaces/ecpg/ecpglib/execute.c
+++ b/src/interfaces/ecpg/ecpglib/execute.c
@@ -1310,8 +1310,8 @@ ecpg_build_params(struct statement * stmt)
 		if ((position = next_insert(stmt->command, position, stmt->questionmarks, std_strings) + 1) == 0)
 		{
 			/*
-			 * We have an argument but we dont have the matched up placeholder
-			 * in the string
+			 * We have an argument but we don't have the matched up
+			 * placeholder in the string
 			 */
 			ecpg_raise(stmt->lineno, ECPG_TOO_MANY_ARGUMENTS,
 					   ECPG_SQLSTATE_USING_CLAUSE_DOES_NOT_MATCH_PARAMETERS,
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 34e62c3d99..114b9ceed9 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -2523,7 +2523,7 @@ pltcl_SPI_execute_plan(ClientData cdata, Tcl_Interp *interp,
 	}
 
 	/************************************************************
-	 * If there was a argtype list on preparation, we need
+	 * If there was an argtype list on preparation, we need
 	 * an argument value list now
 	 ************************************************************/
 	if (qdesc->nargs > 0)
diff --git a/src/test/regress/expected/rowsecurity.out b/src/test/regress/expected/rowsecurity.out
index 1287fceb79..ffee995cff 100644
--- a/src/test/regress/expected/rowsecurity.out
+++ b/src/test/regress/expected/rowsecurity.out
@@ -1614,7 +1614,7 @@ SET SESSION AUTHORIZATION regress_rls_bob;
 INSERT INTO document VALUES (79, (SELECT cid from category WHERE cname = 'technology'), 1, 'regress_rls_bob', 'technology book, can only insert')
     ON CONFLICT (did) DO UPDATE SET dtitle = EXCLUDED.dtitle RETURNING *;
 ERROR:  new row violates row-level security policy for table "document"
--- UPDATE path is taken here.  Existing tuple passes, since it's cid
+-- UPDATE path is taken here.  Existing tuple passes, since its cid
 -- corresponds to "novel", but default USING qual is enforced against
 -- post-UPDATE tuple too (as always when updating with a policy that lacks an
 -- explicit WCO), and so this fails:
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 3f9592f2b5..7d6f0beb49 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2726,7 +2726,7 @@ Rules:
  NOTIFY rules_src_deletion
 
 --
--- Ensure a aliased target relation for insert is correctly deparsed.
+-- Ensure an aliased target relation for insert is correctly deparsed.
 --
 create rule r4 as on insert to rules_src do instead insert into rules_log AS trgt SELECT NEW.* RETURNING trgt.f1, trgt.f2;
 create rule r5 as on update to rules_src do instead UPDATE rules_log AS trgt SET tag = 'updated' WHERE trgt.f1 = new.f1;
diff --git a/src/test/regress/sql/rowsecurity.sql b/src/test/regress/sql/rowsecurity.sql
index dbfb4d7524..8420f0b438 100644
--- a/src/test/regress/sql/rowsecurity.sql
+++ b/src/test/regress/sql/rowsecurity.sql
@@ -593,7 +593,7 @@ SET SESSION AUTHORIZATION regress_rls_bob;
 INSERT INTO document VALUES (79, (SELECT cid from category WHERE cname = 'technology'), 1, 'regress_rls_bob', 'technology book, can only insert')
     ON CONFLICT (did) DO UPDATE SET dtitle = EXCLUDED.dtitle RETURNING *;
 
--- UPDATE path is taken here.  Existing tuple passes, since it's cid
+-- UPDATE path is taken here.  Existing tuple passes, since its cid
 -- corresponds to "novel", but default USING qual is enforced against
 -- post-UPDATE tuple too (as always when updating with a policy that lacks an
 -- explicit WCO), and so this fails:
diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql
index 14b2276bf1..405d83f243 100644
--- a/src/test/regress/sql/rules.sql
+++ b/src/test/regress/sql/rules.sql
@@ -997,7 +997,7 @@ create rule r3 as on delete to rules_src do notify rules_src_deletion;
 \d+ rules_src
 
 --
--- Ensure a aliased target relation for insert is correctly deparsed.
+-- Ensure an aliased target relation for insert is correctly deparsed.
 --
 create rule r4 as on insert to rules_src do instead insert into rules_log AS trgt SELECT NEW.* RETURNING trgt.f1, trgt.f2;
 create rule r5 as on update to rules_src do instead UPDATE rules_log AS trgt SET tag = 'updated' WHERE trgt.f1 = new.f1;