it的用法（27张）.ppt

* * * * * * * Grammar The use of “it” it作代词 一. it作形式主语 二. It作形式宾语 三. it特殊句型 四. it常用的固定搭配 2.It is no good smoking. 3.It is likely that he will become addicted to it. 1.It is bad to smoke. 一、it用作形式主语 用以平衡句子结构，用it来替代作主语的从句、动词不定式、动名词，而把真正作主语的从句、动词不定式、动名词置于句尾。 对于我们来说，努力学习英语很必要。 It is necessary ____us to work hard on English. for 你把真相说出来了，真诚实。 It is honest ___you to tell me the truth. of To work hard on English is necessary for us. You are honest to tell me the truth. It’s + adj + of / for sb. to do sth （1）It is adj.for sb.to do sth. It is illegal for him to drive a car without a license. 1. 替代作主语的动词不定式 此处adj. 通常为描述事件的形容词：easy，difficult，hard，tough，necessary，unnecessary，possible，impossible，likely，unlikely，right，wrong，important，unimportant，legal，illegal，polite，impolite，clear，obvious，certain，suitable，proper，fit，useful，useless，dangerous… 　　 To drive a car without a license is illegal for him. （2）It is adj. of sb. to do sth. Its kind of you to help me with the problem. 此处adj. 通常为描述人的形容词：kind，unkind，nice，rude，cruel，selfless，thoughtful，thoughtless，careful，careless，silly，foolish，stupid，clever，wise，crazy, generous, etc. You are kind to help me with the problem. 1. 替代作主语的动词不定式 It is no good/no use/ useless doing … It is (well) worth doing … It is a waste of money/ time/ energy doing… It‘s (well) worthwhile doing/ to do… It’s great fun doing… 2. It替代作主语的动名词的常见句型 Its no use crying over spilt milk. 覆水难收 3. it作形式主语替代主语从句 It is amazing that at my age I’m still fit enough to cycle 20 km in an afternoon. It is obvious that James’ grandpa lives a very active and healthy life. It is still a question whether we will hold the meeting as planned. ①It is adj. +clause (important, vital, necessary, surprising, amazing, natural, ridiculous, unbelievable, etc) said reported believed It is thought that ... known told hoped