sing的过去分词和过去式分别为sung和sang。sing在英语中可以作动词和名词，当作名词时，意为呜呜声、嗖嗖声、歌唱会，当作动词时，有唱、演唱、啼、呜呜作响等含义。
1、当sing作为名词时，意为呜呜声，嗖嗖声;歌唱会。
例句：Suddenly his mind filled with the recollection of a song she used to sing
突然，他记起了一首她过去经常唱的歌。
2、当sing作为动词时，意为唱(歌);演唱;鸣;啼;啼啭;呜呜作响;发嗖嗖声；其中第三人称单数为sings，现在分词为singing，过去式为sang，过去分词为sung。
例句：I just can't sing in tune!
我一唱就走调！
Now I'd like to sing a song by the Beatles.
现在我来唱一首披头士乐队的歌。
The birds were singing outside my window.
鸟儿在我窗外啼啭。
I sing about love most of the time
我大多唱爱情歌曲。
He started to sing and I joined in.
他开始唱起歌来，然后我也跟着唱起来。
