不定式的復(fù)合結(jié)構(gòu)：for sb/sth to do sth
"介詞for+名詞/代詞"表示不定式的邏輯主語(yǔ),常用于“It is + adj.+ for sb.+ to do sth.”結(jié)構(gòu).
不定式的邏輯主語(yǔ)不能明確是誰(shuí)時(shí),是不用復(fù)合結(jié)構(gòu)的,即：to do sth；否則,用復(fù)合結(jié)構(gòu).
不定式的句法作用舉例如下：
1.主語(yǔ):It is very important for you to study English.
2.表語(yǔ):The car is for you to drive.
3.狀語(yǔ):The man works hard for his boss to be pleased.
4.定語(yǔ)：There is no need for you to go to the office.
5.賓語(yǔ)：I've arranged for her to see you off.