diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 16240f7e39..e7dcaca3b0 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1523,7 +1523,7 @@
        <entry><type>text</type></entry>
        <entry>
          Format a string.  This function is similar to the C function
-         <function>sprintf</>; but only the following conversions
+         <function>sprintf</>; but only the following conversion specifications
          are recognized: <literal>%s</literal> interpolates the corresponding
          argument as a string; <literal>%I</literal> escapes its argument as
          an SQL identifier; <literal>%L</literal> escapes its argument as an
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 2373d52c0f..08ee93b8ea 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -421,7 +421,7 @@ AlterObjectNamespace(Relation rel, int oidCacheId, int nameCacheId,
 		if (Anum_owner <= 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-					 (errmsg("must be superuser to SET SCHEMA of %s",
+					 (errmsg("must be superuser to set schema of %s",
 							 getObjectDescriptionOids(classId, objid)))));
 
 		/* Otherwise, must be owner of the existing object */
diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index 030a283e81..bcde19c71b 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -119,7 +119,7 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
 			if (readlink(fullpath, linkpath, sizeof(linkpath) - 1) == -1)
 			{
 				ereport(WARNING,
-				  (errmsg("unable to read symbolic link %s: %m", fullpath)));
+				  (errmsg("could not read symbolic link \"%s\": %m", fullpath)));
 				continue;
 			}
 
@@ -363,7 +363,7 @@ SendBaseBackup(BaseBackupCmd *cmd)
 	dir = AllocateDir("pg_tblspc");
 	if (!dir)
 		ereport(ERROR,
-				(errmsg("unable to open directory pg_tblspc: %m")));
+				(errmsg("could not open directory \"pg_tblspc\": %m")));
 
 	perform_base_backup(&opt, dir);
 
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 470e6d170d..63952e73f1 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -515,7 +515,7 @@ ProcessRepliesIfAny(void)
 			default:
 				ereport(FATAL,
 						(errcode(ERRCODE_PROTOCOL_VIOLATION),
-						 errmsg("invalid standby message type %d",
+						 errmsg("invalid standby message type \"%c\"",
 								firstchar)));
 		}
 	}
@@ -566,7 +566,7 @@ ProcessStandbyMessage(void)
 		default:
 			ereport(COMMERROR,
 					(errcode(ERRCODE_PROTOCOL_VIOLATION),
-					 errmsg("unexpected message type %c", msgtype)));
+					 errmsg("unexpected message type \"%c\"", msgtype)));
 			proc_exit(0);
 	}
 }
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index d1113ed5d3..3677b1c3bb 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -3887,7 +3887,7 @@ text_format(PG_FUNCTION_ARGS)
 		if (arg > PG_NARGS() - 1)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("too few arguments for format conversion")));
+					 errmsg("too few arguments for format")));
 
 		/*
 		 * At this point, we should see the main conversion specifier. Whether
@@ -3908,7 +3908,7 @@ text_format(PG_FUNCTION_ARGS)
 			default:
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-						 errmsg("unrecognized conversion specifier: %c",
+						 errmsg("unrecognized conversion specifier \"%c\"",
 								*cp)));
 		}
 	}
diff --git a/src/test/regress/expected/text.out b/src/test/regress/expected/text.out
index f5cb5e2509..e45714f77e 100644
--- a/src/test/regress/expected/text.out
+++ b/src/test/regress/expected/text.out
@@ -171,11 +171,11 @@ select format('Hello %%%%');
 
 -- should fail
 select format('Hello %s %s', 'World');
-ERROR:  too few arguments for format conversion
+ERROR:  too few arguments for format
 select format('Hello %s');
-ERROR:  too few arguments for format conversion
+ERROR:  too few arguments for format
 select format('Hello %x', 20);
-ERROR:  unrecognized conversion specifier: x
+ERROR:  unrecognized conversion specifier "x"
 -- check literal and sql identifiers
 select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, 'Hello');
                  format                 
@@ -219,15 +219,15 @@ select format('%1$s %12$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
 
 -- should fail
 select format('%1$s %4$s', 1, 2, 3);
-ERROR:  too few arguments for format conversion
+ERROR:  too few arguments for format
 select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
-ERROR:  too few arguments for format conversion
+ERROR:  too few arguments for format
 select format('%1s', 1);
 ERROR:  unterminated conversion specifier
 select format('%1$', 1);
 ERROR:  unterminated conversion specifier
 select format('%1$1', 1);
-ERROR:  unrecognized conversion specifier: 1
+ERROR:  unrecognized conversion specifier "1"
 --checkk mix of positional and ordered placeholders
 select format('Hello %s %1$s %s', 'World', 'Hello again');
             format