We often hear the girl sing on the playground

We often hear the girl sing on the playground we often hear the girl ( ) (sing) song. we often hear the girl sing this song转被动 we often hear her sing the song 将We often hear the girl sing happily in her room改为被动语态 We often ___(play) on the playground. i often hear the girl _____(sing) loudly. I often hear the lonely girl sing in her room 改被动:We often hear them sing in the classroom. 分析句子成分：We often hear him sing in the hospital. 1.We often hear the song ____(sing) in English. We often hear her sing in the next room中为什么用sing而不用sings