For me "How about" is used as a suggestion. "What about" is more of a response. How about we meet at one then go to the pub to watch the match? What about meeting at 1.30 in the pub?

Hmm, there isn't really much of a difference to be honest. I think the difference would be that with "how about" you're making a suggestion whereas with "what about" it can be either a suggestion or a question. The way you phrase things can also be slightly different, but understanding that just comes with experience. Some examples would be How about we leave here at 9/what about if we leave here at 9 How about that one instead/what about that one instead In my opinion "how about" is slightly stronger (but still generally polite) Some examples though when they are not interchangeable What about that essay bothered you? What about what I just said offended you? (note: these examples look kind of funny written down, but conversationally things like this are said often)

One thing you might want to remember: "How about....." is a short way of saying "How do you feel about....." Because you are being asked how you feel about something - it is a little more personal, also a little more casual. Keep in mind that native English speakers (especially Americans) are much more comfortable being personal or casual with others. They will use this kind of language with complete strangers! Our language doesn't have a formal case (Lei per esempio) so we do this with very little changes in language and body language....and we do not take it very seriously in general.