When you open Kaizena, you'll see all the messages your teacher has given you:
Most comments will be attached to a highlight on your file. The part in the colored box is the text that's highlighted:
The comment underneath is the feedback your teacher gave you:
If you aren't sure which comment goes with which highlight, you can click the comment at the right, or the highlight on the file. This will make the highlight brighter and will open the comment.
Replying to a comment
Once you've opened a comment, you can reply to it.
Click the microphone to reply with a voice comment:
Or click the "T" to reply with a text comment:
The reply will be attached to the first comment, like this: