常用it作形式主语的句型结构◊It+be+形容词+that-从句可用于此句型的形容词有:wonderful,true，good，right，wrong，(un)important，useless，surprising，clear，unusual，lucky，certain,necessary等。女口：①Itisquitecertainthathewillbeatthemeeting.②Itissurprisingthathecamelatetoschoolthismorning.③Itisimportantthatwe(should)studyhard注意：该句型中的形容词是(un)important,necessary等时，从句应为(should)+动词原形。◊It+be+-ed分词+that-从句适用该句型的过去分词主要有：said,reported,announced,hoped,thought，told，believed,expected,decided,suggested,known等。如：①Itishopedthatonedaytheywillhaveenoughanimalstosetthemfree②Itiswellknownthattheearthgoesaroundthesun.③Itissuggestedthatthesportsmeeting(should)beputoffuntilnextweek.注意：该句型的过去分词是suggested时，从句应为(should)+动词原形。◊It+be+名词+that-从句适用该句型的名词(词组)有：apity，anhonor，agoodthing，afact，asurprise，goodnews,one'sduty等。如I:①Itisapity(that)youmissedthesportsmeetinglastweek.②ItisafactthatEnglishisbeingacceptedasaninternationallanguage.It+seem/appear/happen的适当形式+that从句。该句型常可以转换成含不定式的简单句。如：①Itseemsthatthereisabigwastepipecomingdownfromthetown.—Thereseemstobeabigwastepipecomingdownfromthetown.②Heappearedtobecalm,butinsidehisheartwasbeatingwildlywithfear.—Itappearedthathewascalm,butinsidehisheartwasbeatingwildlywithfear.◊Itdoesn'tmatter(It'snowonder;Itdoesn'tmakemuchdifferenee等)＋when/where/which/whether等从句。如：①Doesitmatterifhecan'tfinishthejobontime?②Theyareallclassmates.Itisnowondertheyshouldhelpeachotherwiththeirstudies.◊It+be+adj./n.(forsb./ofsb.)+todosth.该句型中的形容词通常是表示事物的特点或特征的如difficult，hard，easy，impossible，necessary，important等，此时用for;或表示人的性格特征或特点的如nice,good,bad,kind,silly,foolish,wise,clever,careless,rude,brave,cruel,careful,grateful等，这时要用of。如：①Itisfoolishofyoutogiveupsuchagoodchance.②ItisnecessaryforcollegestudentstomasteratleastaforeignlanguageIt作形式主语常见句型动词不定式,动名词或主语从句作主语时,通常把它们放在谓语动词前,而用it作形式主语，放到句首，常见句型有：1.It+be+形容词+主语从句，如：ItisuncertainwhetherhecancometoJenny'sbirthdaypartyornot.2.It+be+名词词组+主语从句，这类名词有:afact,apity,ashame,anhonour，aquestion等，如：It'sapitythatyoumissedtheexcitingfootballmatch.Itremainsaquestionwhetherhewillcomeornot.3.It+be+过去分词+主语从句，这类过去分词有:announced,believed,expected,hoped,decided,reported,said,shown等，如:Itisreportedthat16peoplewerekilledintheearthquake.Itisnotdecidedwhowillgivetheoperationtothepatient.4.It+不及物动词(seem,appear,happen等)+主语从句，这类不及物动词有:appear,happen,seem等，如：Itseemedthathedidn'ttellthetruth.IthappenedthatIwasoutwhenhecalled.5.It+be+形容词+forsb.)+动词不定式•>l」o/v\①-C1-C七/v\①uud-①-C01noA40pups"II二-DC。理ssM^ttjigsMlffng飾崔别凶屆YwosfraEap.sus・lls匸os>__『o七oduqo七odWS=OO4UOAOP.mdrusouc・P.E氓呂、ng^^ssaE^a・llg昭SIQIISM啾(BE®飾崔粼凶、恒锻£®e+・qs4。++aq+41・9ospw、o一qwsodQuetioduq・p」ella-mE-p>seo-w®^崔粼ia•lue/v\A①£」Q>①一£/v\u①」p-zo£1Q>601①s-/v\uns一-IOj6en6ue-U6Q」O405」sseuu016unoA£1」04Xjess①。①us"II-mrqs吕儘恒锻氐炮從、wr拓see恒锻氐孵哩z«些富趣、Eesfraspvv、a-q-ssodQuetoduq©ellQ-rDE-p>sea®飾崔旺IBESHI?粼凶d」OUJAue」£016upl-el①uu一一40①一se/v\es"II二亦廟ssoosuos.ssoosn.40o4se/weosnou・POO6ou・POO6-啾IBEIBEI...
