将这句被动语态还原成主动语态的句子是“sb often heard the girl sing this English song in her room”,hear这个词的宾补结构在主动语态中有hear sb do sth这种,是省去了to的不定式(请比较ask sb to do sth),但在被动语态中,补语部分的to要补回来,所以是to sing
类似的动词还有make、let、have,see、feel等等
将这句被动语态还原成主动语态的句子是“sb often heard the girl sing this English song in her room”,hear这个词的宾补结构在主动语态中有hear sb do sth这种,是省去了to的不定式(请比较ask sb to do sth),但在被动语态中,补语部分的to要补回来,所以是to sing
类似的动词还有make、let、have,see、feel等等