［特殊詞精講］forget doing/to do

　　The light in the office is stil on. He forgot to turn it off. 辦公室的燈還在亮著，他忘記關(guān)了。(沒有做關(guān)燈的動作)

　　He forgot turning the light off. 他忘記他已經(jīng)關(guān)了燈了。(已做過關(guān)燈的動作)

　　典型例題

　　---- The light in the office is still on.

　　---- Oh，I forgot___.

　　A. turning it off　 B. turn it off　 C. to turn it off　 D. having turned it off

　　答案：C.由the light is still on 可知燈亮著，即關(guān)燈的動作沒有發(fā)生，因此用forget to do sth.而forget doing sth表示燈已經(jīng)關(guān)上了，而忘記了這一事實(shí)。此處不符合題意。