it做形式主語用法大全

1、It作形式主語常見句型作形式主語常見句型動詞不定式，動名詞或主語從句作主語時，通常把它們放在謂語動詞前，而用it作形式主語，放到句首，常見句型有：1.Itbe形容詞形容詞主語從句，如：主語從句，如：ItisuncertainwhetherhecancometoJenny’sbirthdaypartynot.2.Itbe名詞詞組名詞詞組主語從句，這類名詞有：主語從句，這類名詞有：afactapityashameanhonour，aques

2、tion等，如：等，如：It’sapitythatyoumissedtheexcitingfootballmatch.Itremainsaquestionwhetherhewillcomenot.3.Itbe過去分詞過去分詞主語從句，這類過去分詞有：主語從句，這類過去分詞有：announcedbelievedexpectedhopeddecidedreptedsaidshown等，等，如：如：Itisreptedthat16people

3、werekilledintheearthquake.Itisnotdecidedwhowillgivetheoperationtothepatient.4.It不及物動詞不及物動詞(seemappearhappen等)主語從句主語從句這類不及物動詞有：這類不及物動詞有：appearhappenseem等，等，如：如：Itseemedthathedidn’ttellthetruth.IthappenedthatIwasoutwhenhec

4、alled.5.Itbe形容詞形容詞fsb.）動詞不定式動詞不定式這類句型常用形容詞這類句型常用形容詞easydifficulthardimptantpossible，wise等作表語，有時候等作表語，有時候為了強調(diào)不定式動作的執(zhí)行者，常在不定式前加為了強調(diào)不定式動作的執(zhí)行者，常在不定式前加fsb，如：，如：It’snecessaryftheyoungtomastertwofeignlanguage.Itisunwisetogiveth

5、echildrenwhatevertheywant.這類形容詞有：這類形容詞有：easydifficulthardimptantpossible，wise6.Itbe形容詞形容詞ofsb.動詞不定式，這類形容詞常是表示心理品質(zhì)動詞不定式，這類形容詞常是表示心理品質(zhì)性格特征的性格特征的形容詞，如：形容詞，如：kindnicestupidcleverfoolishpoliteimpolitesillyselfishconsiderate等。

6、等。某人和這些形容詞可以構(gòu)成主系表結(jié)構(gòu)。如：某人和這些形容詞可以構(gòu)成主系表結(jié)構(gòu)。如：It’sverykindofyoutohelpmewiththewk.=Youarekindtohelpme.Itseemedselfishofhimnottosharehisdictionarywithothers.=Heseemedselfishnottosharehisdictionarywithothers.7.Itbe名詞詞組名詞詞組動詞不定式

7、，如：動詞不定式，如：Itisnotagoodhabittostayuptoolate.8.Itbe名詞或形容詞名詞或形容詞動名詞，這類名詞和形容詞常常是：動名詞，這類名詞和形容詞常常是：goodnogoodnouseawasteofuselesssenseless等，如：等，如：It’sawasteoftimetalkingtoheranyme.Itisnousearguingaboutthematterwithhim.9.Ittak

8、e(sb.)時間（金錢）時間（金錢）動詞不定式，如：動詞不定式，如：Ittookthewkersalmostthreeyearstofinishbuildingthedam.Itwilltakeawholedaytogettothetopofthemountainonfoot.實戰(zhàn)演練：實戰(zhàn)演練：1.Itisgenerallyconsideredunwisetogiveachildheshewants.(NMET1997)A.howev

9、erB.whateverC.whicheverD.whenever2.Infactisahardjobfthepolicetokeepderinanimptantfootballmatch.(2001上海上海)A.thisB.thatC.thereD.it3.isafactthatEnglishisbeingacceptedasaninternationallanguage.(NMET1995)A.ThereB.ThisC.ThatD.

10、It4.Isnecessarytotakeoffourshoeswhenweenterthelab(MET88)A.everyoneB.thisC.herD.it5.________willtakeyoualotoftimetofindhiminthecrowd.A.ItB.IC.WeD.They6.Itisnousehis_________therethesituationishopelessnow.A.togoB.tobegoing

11、C.goingD.havinggone7.Itisnevertoolatetolearn________A.isitB.isn’titC.doesitD.doesn’tit8.___________isknowntoallthatShenzhouVILaunchedSuccessfully.A.AsB.WhatC.ItD.That9._______isreptedinthenewspapertheEarthquakeineastChin

12、asJiangxiProvincekilled13peopleA.ItB.AsC.ThatD.What10.___________certainthathisinventionwillmakepeople’slifeconvenient.A.That’sB.ThisisC.It’sD.What’s11._________thatthereisanotherfootballmatchontheairthisevening.A.Itsays