两个都是合成词,是疑问词+后缀ever
疑问词的各种用法
no matter +疑问词" 或"疑问词+后缀ever"
例如：
No matter what happened, he would not mind. =Whatever happened, he would not mind.
不管发生什么,他不在意.
替换：
no matter what = whatever
no matter who = whoever
no matter when = whenever
no matter where = wherever
no matter which = whichever
no matter how = however
注意：no matter 不能引导主语从句和宾语从句.
(错）No matter what you say is of no use now.（对）Whatever you say is of no use now. 你现在说什么也没用了.（Whatever you say是主语从句）
（错）Prisoners have to eat no matter what they're given.
（对）Prisoners have to eat whatever they're given.囚犯们只能给什么吃什么.