I am new in ELL, i have read various question where user ask meaning of more than one word or phrase. Sometimes one part of the question is easy to answer, but the second is not. So do we accept answers which only answer part of the question?
One of my own partial answer for the reference. It would be okay to remove it, if we don't accept these kinds of answers.
This is one reason users are encouraged to ask only one question per question, but sometimes that line can get fuzzy.
Let's assume, though, for a moment, that there's a question where it doesn't make sense to post two questions. Let's also assume this question has an easy part, and a hard part. I would say that if you're only answering the easy part of the question, perhaps it would be best to leave a comment, instead of writing an answer. But if you're answering the hard part, it's okay to leave an answer and leave the easy part unaddressed.
This depends on the situation, though. If the easy part is only easy for you because of some kind of expertise you have (so it's unlikely to be easy for the rest of the community), I might leave that as an answer, but I'd probably explicitly mention that I'm not so sure about the other part of the question.
Fact is, some questions will be difficult to answer with a single answer. If your answer can stand alone amidst a group of answers, and add something helpful for the O.P. and interesting to the community, go ahead and leave it as an answer. On the other hand, if you are merely stating the obvious, you might want to use a comment instead.
Moderators can turn answers into comments. In fact, other users can flag an answer when they believe that's what should be done.
In the specific instance you asked about, the O.P. is relatively new, and is feeling their way around ELL. I wouldn't be surprised if that question gets modified some. If there's any fault there, I think it rests more with the question than with your answer.
Thanks for asking about the matter here.
Personally, I'm all for it. You may not get the +15 for accepted answer but your answer should get nice upvotes along with any other that adds the third. Just don't get jealous, disappointed or angry if someone compiles your answer with another and posts as their own, getting top score and accepted answer. That happens and will happen, and is not even unfair - after all objectively speaking their answer is superior to both.
Sometimes I found myself quite surprised as I would add to someone's full answer: they post THE canonical answer that is the single, correct, best way to answer it. I post "X's answer gives the essential solution. Let me add some tricks how to approach it in edge cases, how to react to some caveats, and how to cludge a replacement when you have no time/patience for the correct solution." And then, to my surprise, I find mine to get a slew of upvotes overshadowing the full, correct answer. Why? Because mostly everyone knew the canonical answer while I managed to teach them something new. The canonical answer still gets accepted, and I - with my edge-case, partial and late answer that skirts the topic, still get better score.
