1、however作副词，含义为“但是，可是，不过”。多插在句中，有时放在句首或句尾。
However，they did not seem to have much effect.
不过，他们似乎没有起太大的作用。

His first response was to say no. Later, however, he changed his mind.
他最初的反应是不同意，可是后来他改变了主意。

He said that it was so; he was mistaken，however.
他说事情就是这样；然而，他错了。