If you have allowed liking for a course discussion, you can like discussion replies.
If the steps in this lesson do not match what is displayed in your course, learn how to like replies in the Discussions Redesign interface.
In Course Navigation, click the Discussions link.
Click the name of the discussion.
Locate the reply and click the Like icon.
The Like icon will change from gray to blue, indicating you have liked the reply [1].
When a reply is liked, the Like icon will also display the total number of likes for all users in the discussion [2].