however，no matter how
However和no matter how同义，都表示无论如何的意思，又都引导让步状语从句，但它们的修辞意味和使用场合有所不同。
However是比较正式的用语，大都用于书面语，口语中较少使用；no matter how则比较口语化，它的语势比however重，故常用在强调的场合。请看下面的例句：
The task must be done，however arduous it may be．
无论多么艰难，这个任务一定要完成。
（试比较一般句：The task must be done though it is arduous．）
Ill take your words，no matter how harsh they may be．
无论语气多么难听，我还是听你的话的。
（试比较一般句：Although your words are harsh，Ill take them．）
However有时可表达然而、可是之意，出现于句中或句尾。例：
They said that it was so；they were mistaken，however．
他们说事情就是如此，可是他们错了。
与之类似区别的词语很多，例如whatever/no matter what、whenever/no matter when、wherever/no matter where、whichever/no matter which、whoever/no matter who.