what about和how about,why not的区别是具体用法，不是意思 注意是"具体用法"!

what about how about 后接动词的 -ing形式。
why not 后接动词原形

what about= how about 后面加名词或代词， 例如：What about going to the park?
而why not 后面加动词原形， 例如：Why not go to the park?
它们都可以表示提建议

what about /how about后接名词或动词的ing形式。而why not 后面接动词原形。
如 what about going to the zoo?
Why not go to the zoo?

what about和how about基本无区别 后面加doing
why not后加do

what about和how about都表示怎么样？可以互换后面加动词的话，动词要加ing
why not是为什么不？后边用动词原形

what about和how about是怎么样后接doing sth
why not等于why don't you为什么不呢 后接do sth

what about how about 后接动词的 -ing形式.
why not 后接动词原形.都可以用来给别人提建议.给你例子：
What /How about going swimming?=Why not go swimming?
Why not play basketball?=What /How about playing basketball?

区别不大，仅存在于口头用语。类似汉语中的“这么来做……怎样？”；“这样来做……怎样”；“为什么不呢”