1.whatever whoever whichever whenever ---引导名词性从句或状语从句
Whatever he do,he is always careful.
He may do whatever he wants to do
2.no matter what no matterwho no matter which no matter when---只引导状语从句
No matter what he do,he is always careful
=Whatever he do,he is always careful
说明：在状语从句 *ever 可取代no matter *