Resolved a grammatical error
@@ -17,7 +17,7 @@ type ActionFunc func(*Context) error
// CommandNotFoundFunc is executed if the proper command cannot be found
type CommandNotFoundFunc func(*Context, string)
-// OnUsageErrorFunc is executed if an usage error occurs. This is useful for displaying
+// OnUsageErrorFunc is executed if a usage error occurs. This is useful for displaying
// customized usage error messages. This function is able to replace the
// original error messages. If this function is not set, the "Incorrect usage"
// is displayed and the execution is interrupted.
