What about/how about?

Hello,

      May I ask about "what about/how about"? So far as I have been aware of, these 2 phrases are used to offer the suggestion. I'm not sure as sometimes when one answers a question and then he/she will also ask, "What about you?" For example; A: What did you do last weekend?

                   B: I went to the central park. It was really fun. What about you?

Does "B" use "what about you?" correctly? Thank you very much.

Hi! Great question. Yes, "B" uses "what about you?" correctly. We often use this phrase, or "How about you?" when we want to ask the other person the same question as he or she just asked us. 

We can also use these phrases, as you said, to offer suggestion.

Thanks!

Amy