Use “How about?” to give suggestion.
A: I’ve got the day off from work tomorrow. What should we do?
B: How about going to the cinema?
A: Nah. I don’t really feel like going out.
B: How about we just rent a DVD and watch it at home?
A: That sounds good.
“How about?” can be followed by verb-ing or by a pronoun and verb1.
• How about going to the cinema?
• How about we rent a DVD?
“What about?” is often used when someone is asking for an opinion to a choice.
• What about the green one? That looks pretty on you.
We can also use “What about?” to mention an objection.
A: Let’s spend the weekend in the city.
B: But what about my piano lesson on Saturday?
A: That’s no problem, just talk to the teacher and reschedule it.
“How about you?” or “What about you?”
“How have you been?” — “Good. A little busy with school. How about you?”
“Where do you work?” — “At a law firm. What about you?”
In this case, “How about you?” and “What about you?” are asking the same question back to the other person.