it用法小结 (2)

Theusageof“it”Grammarofunit3-4一、用作代词1.代替上文中提到的同一事物。Ican’tfindmyticket，IthinkImusthavelostit.2.表示时间、天气、季节、距离等。It’sfouro’clocknow.Itwasnearlymidnightwhenwegothome.3.指代无生命的东西，或性别不详时，用“it”指代动物，幼童等。Thebabyiscrying,forit’shungry.Whoisit?It’sme.二、用作形式主语当不定式，动名词，从句等用作主语时，为避免句子头重脚轻，常在句首使用形式主语“it”，而把真正的主语后置。It用作形式主语的几类句式1.用作动词look,seem,appear,happen,occur等的形式主语，后接that从句或asif从句。Itseemsthatheknowseverything.It(so)happenedthatIhadnomoneywithme.2.当系表结构后接由if或when引导的状语从句时，在系表结构前使用形式主语表示说话人对某情况的看法。Itwasagreatsurprisetomewhenhedidathinglikethat.3.用于ifitwerenotfor……或ifithadn’tbeenfor……(表示“若不是因为……”)4.“It+be+adj+to+do”这类形容词有：easy,difficult,hard,important,possible等.Itisimpossibletomasteraforeignlanguageinthreedays.5.It＋be+n/adj+v-ing,这类名词或词组有：nogood,nouse,nopleasure,useless,senseless,worth,worthless,awasteoftime/money.Itisnousearguingaboutthematterwithhim.5.It(形式主语)+be+v-ed+主语从句，这类过去分词有：announced,thought,hoped,decided,reported,said,known等.。Itissaidthathewillbebackhometomorrow.6.“Itis＋n+主语从句”,这类名词有：fact,pity,shame,honor,nowonder等.Itisapitythatyoumisstheexcitingfootballmatch.7.“It(形式主语)+be+adj.+that从句”，这类形容词有：necessary,strange,likely,natural等.Itisstrangethathefinishhishomeworkontime.三、用作形式宾语作形式宾语,代替由不定式、动名词或从句表示的真正宾语。其主要基本句型有以下几类。1.主语＋谓语＋it(形式宾语)＋宾语补足语＋todosth.(doingsth.或that从句).这类词有：make,think,find,consider,feel,suppose等.Doyouthink___difficulttoworkoutthismathsproblem?A.thatB.veryC.yourselfD.it2.“V+it+if/when从句”该句型中常用的动词有：enjoy,like,dislike,hate,prefer,appreciate等.Hehatesitwhenpeopleusehisbike.3.“动词+介词+it+that从句”能用于该句型中的动词短语有：dependon,answerfor,seeto,insiston,askfor.She’llanswerforitthathepassestheexam.