he wasn't heard to sing in the classroom.为什么是to sing,不是singing或其他

显示全部楼层 · 2012-7-28 19:23:29

还原一下句子：We didn't hear him sing in the classroom.句子使用了 hear sb do sth 改为被动语态是：sb be heard to do sth,如果原句是：We didn't hear him singing in the classroom.改为被动语态就是：He wasn't heard singing in the classroom. 【俊狼猎英】团队为您解答。...

千问 · 2012-7-28 19:23:29

nihao be heard singing ------强调被听到的时候正在唱歌 be heard to sing ------强调唱歌的全过程都被听到了...

千问 · 2012-7-28 19:23:29

因为这里并不强调他正在唱歌这个动作，有没有唱歌这样一个基本事实，所以不必用ing形式，hear someone do something的被动语态是加to 的不定式，所以只能用to sing希望选为满意答案...

千问 · 2012-7-28 19:23:29

这里是被动语态，被听见做某事是be heard to do sth...

千问 · 2012-7-28 19:23:29

hearto do 表示动作的全过程hear+ving 表示正在进行...