diff --git a/mod/lesson/lang/en/lesson.php b/mod/lesson/lang/en/lesson.php
index 594554f2492..b0232f97037 100644
--- a/mod/lesson/lang/en/lesson.php
+++ b/mod/lesson/lang/en/lesson.php
@@ -220,6 +220,7 @@ $string['leftduringtimedsession'] = 'You have left during a timed lesson.';
 $string['leftduringtimed'] = 'You have left during a timed lesson.<br />Please click on Continue to restart the lesson.';
 $string['leftduringtimednoretake'] = 'You have left during a timed lesson and you are<br />not allowed to retake or continue the lesson.';
 $string['lesson:addinstance'] = 'Add a new lesson';
+$string['lesson:grade'] = 'Grade lesson essay questions';
 $string['lessonattempted'] = 'Lesson attempted';
 $string['lessonclosed'] = 'This lesson closed on {$a}.';
 $string['lessoncloses'] = 'Lesson closes';