I heard someone sing in the next room. 为什么用 sing

I heard someone sing in the next room. 为什么用 sing I heard someone sing in the next room last night.语法有误吗?I heard someone sing in the next room last nigh.sing要不要改成sang?为什么?这题是sing没错.不用改成singing. I heard him sing in the classroom改为被动语态?someone say it should be modified likehe was heard to sing in the classroom.is that correct? I heard someone( )in the next room last night. A.singing B.sang C.sing D.to sing 选哪个?为什么?谢谢! I often heard () (sing) in the room 3.Someone was shouting.I heard it. I heard him singing there改被动句是heard singing还是heard to sing I singing someone doing heard my honework while was I i heard lucy sing just now 变被动语态 I heard someone______(sing) just now.横线上填什么? I heard some children __(sing) a song just now . I heard it by SHE ,sing的正确行式填空I heard it by SHE .(sing) I heard him singing改为被动语态which is correct?then I heard him sing? i heard her singing.i heard her sing.有什么不同啊? all i need is someone,who makes me wanna sing! i heard someone ( ) a song on my way home I heard someone was badly hurt in the t____ accident . I heard someone is singing.(改为简单句)