Index: wp-includes/class-wp-editor.php
===================================================================
--- wp-includes/class-wp-editor.php	(revision 19826)
+++ wp-includes/class-wp-editor.php	(working copy)
@@ -266,7 +266,8 @@
 				The + sign marks the default language. More information:
 				http://wiki.moxiecode.com/index.php/TinyMCE:Plugins/spellchecker
 				*/
-				$mce_spellchecker_languages = apply_filters('mce_spellchecker_languages', '+English=en,Danish=da,Dutch=nl,Finnish=fi,French=fr,German=de,Italian=it,Polish=pl,Portuguese=pt,Spanish=es,Swedish=sv');
+				/* translators: spellchecker languages menu  */
+				$mce_spellchecker_languages = apply_filters( 'mce_spellchecker_languages', __( '+English=en,Danish=da,Dutch=nl,Finnish=fi,French=fr,German=de,Italian=it,Polish=pl,Portuguese=pt,Spanish=es,Swedish=sv' ) );
 
 				self::$first_init = array(
 					'mode' => 'exact',