sing for的用法和樣例：
例句
- She'll have to sing for her supper if she comes to stay with me--I'm certainly not going to let her stay in bed all morning.
如果她要來同我一起住，吃飯可得干活－－我當然不會讓她整個上午都呆在床上。 - She can't sing for toffee!
她根本不會唱歌！ - The birds sang for them and for them the stars shone, and the whole verdant valley, teeming with richness and increase, gave up its odorous vapors.
小鳥為他們歌唱，群星為他們閃爍、郁郁蔥蔥的山谷到處呈現出豐饒與生機，散發著香噴噴的霧氣。
