typo fix

docs/guide/i18n.md

@@ -71,7 +71,7 @@ Yii tries to load approprite translation from one of the message sources defined
 In the above `app*` is a pattern that specifies which categories are handled by the message source. In this case we're
 handling everything that begins with `app`.
 
-`class` defines which message source is used. There following message sources are available:
+`class` defines which message source is used. The following message sources are available:
 
 - PhpMessageSource that uses PHP files.
 - GettextMessageSource that uses GNU Gettext MO or PO files.