I'm looking at several questions. Sometimes I can comment because there is a clear mechanism to do so, a big edit field similar to the one offered for an answer.
Other times, even on very recent issues, I cannot find how to submit a comment. The topic doesn't look closed in any way I can see and, in some cases, hasn't even been answered yet.
I guess I'm blind, the interface is very busy, whatever the reason, but how do I add a comment when I don't have an answer and don't want to answer, but wish to contribute to what may become an answer?