Q:

Is answering a question with a question always a comment?

In this question I have asked several questions in the comments, which are to a degree rhetorical - they could be considered answers in themselves if the words were rearranged, but the OP doesn't specify whether they are already doing those things so I felt it better to ask for clarification. They are not necessarily good quality answers, because the OP could reply to them "I'm already doing that and it hasn't helped".
Where an answer "Try doing X" could be phrased as a question "Have you tried X?" is it always better to make it a comment to ask the OP to specify in the question whether they have done these things?

A:

Adding half-answers to comments can often lead to comments being turned into discussions, which isn't really what comments are there for. And comments containing answers have a habit of being deleted.
See Comments

You should submit a comment if you want to:

Request clarification from the author;
Leave constructive criticism that guides the author in improving the post;
Add relevant but minor or transient information to a post (e.g. a link to a related question, or an alert to the author that the question has been updated).

Generally speaking, comments under questions should be mainly be there for clarification purposes, and once your clarification has been addressed, it's only polite to delete the comment (it just helps keep things tidy and stops you from looking like you've asked for a clarification for something that's already in the question....)

A:

Personally, I don't think answers are appropriate in this context. In preparation of writing an answer, it seems like a good idea in most cases to ask some questions in the comments to validate some assumptions and prepare a basis for your answer. Without the clarification, the answer runs the risk of missing the mark. This is especially true since 'try doing X' should always be 'try doing X because reason Y'.
In fact, such questions should prompt the OP to edit their question and add the answers to the questions asked in the comments, so that the back-and-forth comments can then be cleaned up.

