不用“人”作主語的習慣

請看下面的句子，答案是哪個？原因是什么？

He is __________ to win the match.

A. possible            B. difficult             C. sure                  D. easy

此題應選C。其余幾項不能選為答案，是因為它們在通常情況下，easy, difficulty, possible, impossible, necessary 等形容詞后接不定式時，通常不以人作主語。請再看實例：

他可能會贏得這場比賽。

誤：He is possible to win the match.

正：It is possible for him to win the match.

我很難按時完成它。

誤：I’m difficult to finish it in time.

正：It’s difficult for me to finish it in time.

他可以輕而易舉地把它干好。

誤：He’s easy to do it well.

正：It’s easy for him to do it well.

他不可能成功。

誤：He is impossible to succeed.

正：It is impossible for him to succeed.

他有必要買臺電腦。

誤：He is necessary to buy a computer.

正：It is necessary for him to buy a computer.

對于以上結構，有些形容詞有時也可用人作主語，但要注意，此時這個主語必須是其后不定式的邏輯賓語。如：

他很容易(難)相處。

正：He’s easy (difficult) to get along with.

正：It’s easy (difficult) to get along with him.