It做形式主语讲解

It做形式主语❤It’snecessaryfortheyoungtomastertwoforeignlanguage.❤It’sawasteoftimetalkingtoheranymore.❤It’sapitythatyoumissedtheexcitingfootballmatch.动词不定式动名词从句形式主语It作为形式主语的用法当不定式、动名词、从句等用作句子主语时，为保持句子平衡，通常把真正的主语放在句末，而在句首使用形式主语it.拒绝是令人遗憾的.记住这一点是很重要的.It’sapitytorefuse.It’sveryimprotanttorememberthis一、代替动词不定式做形式主语①It+be+adj.+（forsb.）todosth.此处adj.通常为描述事件的形容词：easy，difficult，hard，necessary，impossible，important，natural,likely，obvious，useful，useless，dangerous…做某事是…It’snecessaryforustomasteraforeignlanguage.•②It+be+adj.+ofsb.todosth•此处adj.通常为描述人的形容词：kind，nice，rude，cruel，careless，foolish，stupid，wise，crazy…某人做某事，某人是…•eg.It’sfoolishofyoutodriveacarafterdrinking.•It’sverykindofyoutohelpmewithmyEnglish.③It+be+名词词组+动词不定式eg.Itisnotagoodhabittostayuptoolate.常见句型：Ittakes/tooksb.sometime/moneytodosth.Itisnogoodcryingoverspiltmilk.Itisnousecastingpearlsbeforeswine.覆水难收不要明珠暗投，对牛弹琴构成如下结构：Itis+nouse/nogood/notanygood/notanyuse…+doingsth.二、代替动名词作形式主语①It+be+名词词组+主语从句这类名词有：afact,apity,ashame,anhonour，aquestion，asurprise，commonknowledge…eg.It’scommonknowledgethatpeoplecann’tlivewithoutwater.三、代替从句做形式主语②It+不及物动词+that（asif）-从句这类不及物动词有：look，seem，appear，happen，occureg.Itseemsthathedoesnottellthetruth.•Itistime+thatsb.+v-ed/shoulddo•Eg.It’stimethatyouwenttobed•It’stimethatyoushouldgotobed.•It’snecessary/impossible/important/naturalthatsb.(should)do•Eg.It’simportantthatwe(should)keepthebalanceofnature.③It+be+adj.+that-从句④It+be+-ed（过去分词）+that-从句Itissaidthat…据说…Itisreportedthat…据报道…Itissupposedthat…据推测…Itishopedthat…希望…Itiswellknownthat…众所周知…Itisgenerallyconsideredthat…普遍认为…Itissuggestedthat…有人建议…练习：把下列格局转换为it做形式主语的句子1.Hewasrudetosayso.2.Tryingagainisofuse.3.Whenandwheretoholdthepartyhasn’tbeendecided.Itwasrudeofhimtosayso.Itisofusetryingagain.Ithasn’tbeendecidedwhenandwheretoholdtheparty.Thankyou.