i heard lucy sing just now 变被动语态

i heard lucy sing just now 变被动语态 I often heard () (sing) in the room I heard him singing there改被动句是heard singing还是heard to sing 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? They were heard ____（sing）when I walked past.They were heard ____（sing）every morning. I heard someone sing in the next room. 为什么用 sing i heard he （）（sing）at that time.为什么填was sing I don't know lucy,but I the( )girlA heard B knew about C learned D heard ofI don't know lucy,but I ( )the girl Though i have often heard this song( ),i have never heard you ( ) it.A.being sung;sang Bsang;singing C.sung;sing D.to be sung;to sing I heard her ＿（sing） in the next room when I came back. I heard him ____ (sing) when I passed his room该填什么?为什么这样填? 1、When I passed his room,I heard him （）（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. he was heard singing=he was heard to sing?dictionary tells us like this,I don't know why