How?
Type in your comment in the Add a comment… interface, which is below the post. Then, click the green circle button with a paper plane icon to submit your comment.
User Rights
Unless comments are closed, anyone who can see the post can also comment the post.
The user who made the post has the right to close the comments for the post.
School admins can also close comments for any post.
If the comments are closed, the post states, “Commenting is closed for this post.”