不定式for結(jié)構(gòu)在句中可以作主、賓、表、定、狀、同位語：
1．It is easy for Tom to do this work．（主語）湯姆做此工作是容易的.
2．I'd like for him to come here．（賓語）我喜歡他來這里.
3．His idea is for us to travel in two different groups．（表語）他的想法是：我們分成兩組旅行.
4．Have you heard about the plan for you to go abroad．（定語）你聽到讓你出國的計劃嗎?
5．The word is too difficult for him to pronounce well．（狀語）這單詞太難,他念不準(zhǔn).
6．In the most schools,it is the custom for the headmaster to declare the newterm start．在大部分學(xué)校,校長宣布新學(xué)期開始是一個習(xí)慣.
b．不定式of結(jié)構(gòu)只能在句中作主語.
1．It was careless of him to leave his umbrella in the train．他把傘丟在火車上真是太粗心了.
2．It is awfully good of you to come to see me off at the station．謝謝你來車站送我.