Question

英语题 这道题给出的参考答案选A,我想知道为什么不选B???

What did Mr.Black do in the middle of the night?
well, I'm not sure, but he was often heard..................
A. singing the same song
B. to sing the same song
C. sing a same song
D. To be playing same song

Answer 1

因为B的选项是不定式，表示的将要做的动作。但根据题意，应该是常常听到他半夜唱歌，如果用主动语态的话，就是“I often heard him singing the same song.”
而“I heard him to sing the same song”意思是“我听说他要唱歌”。

Answer 2

to do一般表示还没做，将要做的
he was heard是被动，其实暗藏的短语是：hear sb doing sth；变成被动：sb is heard doing sth

Answer 3

使用hear doing的主要原因是often，表示经常，并非一次性。

Answer 4

heard doing sth. 这是词组。