Adding another comment on a already made comment
If we select an underlined text, we can't add a comment or re-underline it.
Would be useful, e.g. to indicate that the learner doesn't know what the correction should be; also, if the learner deletes the underlined text (e.g. using delete/backspace key, or select the text and press backspace/delete), any new text is not underlined anymore.
Tyler puts his corrections (to the red underlines) in brackets in the text. It seems to work well, except that @VictoriaDemierbe can't comment on them because they remained underlined. Thus either they need to not be underlined, or it needs to be possible to comment on an underlined text. It might still be a good idea to add a thumbs-up reaction to both messages and comments in order for the student to quickly acknowledge them without disrupting the flow of the conversation.