专题11 it的用法-备战2021年高考英语语法精讲PPT

语法专题十一　it的用法 考试考点聚焦考点一　it作形式主语 it作形式主语，而把真正的主语置于句子后面是为了使句子平衡。it可代替后面的不定式、动名词、主语从句等。该用法通常用于以下句型： 1．“It is＋形容词/名词/过去分词＋that...”。适用于这个句型的动词有say, announce, decide, learn, know, report, hope, think, believe, expect, suggest等。适用于这个句型的名词有idea, belief, dream, pity, wish, fact, wonder, problem, pleasure等。适用于这个句型的形容词有clear, well­known, important, necessary, strange, urgent等。 It is a pity that I can't go with you. 可惜我不能与你们一起去。 It's necessary that children should learn some knowledge of road safety. 孩子们学一些道路安全知识是有必要的。 特别提示： it作形式主语代替主语从句时，要注意它和as引导的定语从句的区别。试比较： It was reported that the US was under the terrorist attack. 据报道美国遭到恐怖分子袭击。 As was reported, the US was under the terrorist attack. 据报道美国遭到恐怖分子袭击。 2．“It is＋形容词/名词＋不定式”。it作形式主语，代替后面真正的主语——不定式。 It is interesting to listen to music in the evening. 晚上听音乐真有趣。 It is my wish to learn a foreign language well. 学好一门外语是我的愿望。 3．“It is＋形容词＋for/ of sb.＋不定式”。for前面的形容词常常是difficult, necessary, important, quick, easy, long, hard等，这些形容词常常与