when等于什么词组？

when通常是作为连词使用，它有好几层意思。

1 when意思为在同一时间时，可以替换使用的词组有 at the moment that, at the same time that, at the time that, 例句 He decided to give her a call when she was busy cooking dinner.他决定在她做饭的时候打个电话。 

这里面的when就可以用上述任一词组替换。

2 when表示尽管事实上的意思，可替换词组有，by contrast, even if, despite that，例句 Michael decided to play baseball when he could have won many more championships with the Bulls.约翰本可以在公牛队赢得更多冠军时决定打棒球。