runtime(doc): Fix typos in reltime() help. (#13818)

Signed-off-by: Lifepillar <lifepillar@lifepillar.me>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 94fcdf7..9ac79c6 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2024 Jan 04
+*builtin.txt*	For Vim version 9.1.  Last change: 2024 Jan 05
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -7388,9 +7388,9 @@
 			echo startTime->reltime()->reltimestr()
 <
 		Without an argument reltime() returns the current time (the
-		representation is system-dependent, it can not be used as the
+		representation is system-dependent, it cannot be used as the
 		wall-clock time, see |localtime()| for that).
-		With one argument is returns the time passed since the time
+		With one argument it returns the time passed since the time
 		specified in the argument.
 		With two arguments it returns the time passed between {start}
 		and {end}.