of和for的用法与区别,英语问题：for和of用法的区别

1.It’s necessary ___for___us to master a language.

2.It’s unwise ___of___them to refuse our help.

3.It is very important ___for__us to study some rules.

4.It is unpracticable ___for___us to finish such a difficult task

in such short time.

5.It’s wrong __of / for___a person to think only of himself. （这一句for / of 都可以of和for的用法与区别，看你站在什么立场上，出题人不太严谨）

窍门：

如果被认为是普遍现象，就用for,如：

1.It’s necessary ___for___us / people to master a language.

2 It is very important ___for__us / learners to study some rules.

3 .It is unpracticable ___for___us / anyone to finish such a difficult task in two days.

如果被认为是某个人的个别现象，我们就用of,如：

1 It was wrong of me / John / us / the girl to be late again ans again.

2 It is very kind of him to give us so much help. (也就是说，he肯，但别人不一定肯)