1. Click on the 'Comments' icon on the top action bar and the comments-panel will open on the right side of the screen.
2. Select between community or private comment on the top part of the comments-panel.
3. Click on the + icon on the top right side of the comments-panel.
4. Select the segments you want to comment on from the text you are reading.
5. Type your comment and click on the 'Comment' button.