I am not sure how the ability to add comments is structured on the QandA module. I wanted to comment on a question to get some clarification because it wasn't a very clear question. But I don't see a comment box. I only see an answer box. But I know that I have asked questions and had others comment on my question rather than answering. Then once they commented I had the ability to comment.

So is the ability to add an initial comment to a question based on reputation points?  Any details on how this part of the QandA module works would be appreciated.