if用法总结计划.docx

if用法总结计划if的用法总结if的意思和用法：conj.假如，若是;即便;〈口〉能否;假设;n.条件，假想;1.(表示条件)假如,主句用未来时，if从句用此刻时表示未来Hewillcomeifyouinvitehim.假如你请他,他会来的2.(表示虚假)若是,若是时态：可以表示过去，此刻和未来的状况它的基本特色是时态退后同此刻事实相反的假设句型：条件从句主句一般过去时should(would)+动词原形Iftheywerehere,theywouldhelpyou.表示于过去事实相反的假设句型：条件从句主句过去完成时should(would)have+过去分词Thericewouldnothavebeenburntifyouhadbeenmorecareful.Ifshehadworkedharder,shewouldhavesucceeded.IfmylawyerhadbeenherelastSaturday,hewouldhavepreventedmefromgoing.Ifhehadcomeyesterday,Ishould/wouldhavetoldhimaboutit./4含义：Hedidnotcomeyesterday,soIdidnottellhimaboutit.Ifhehadnotbeenillandmissedmanyclasses,hewouldhavemadegreaterprogress.含义：Hewasillandmissedmanylessons,sohedidnotmakegreaterprogress.表示对未来的假想句型：条件从句主句一般过去时should+动词原形were+不定式would+动词原形should+动词原形Ifyousucceeded,everythingwouldbeallright.Ifyouweretosucceed,everythingwouldbeallright.Ifyoushouldsucceed,everythingwouldbeallright.能否=whether连接宾语从句Iwonderifsheisill.不知她能否病了。

连接词conj.1.(表示条件)假如Hewillcomeifyouinvitehim.假如你请他,他会来的2.(表示虚假)若是,若是IfIwereyou,Iwouldneverdothat.假如我是你,我决不做那件事3.(表示退步)即便We'llgoevenifitrains.即便下雨我们也要去能否Iwonderifsheisill.不知她能否病了5.(表示因果关系)每一次...的时候(老是会)IfIfeelanydoubt,Iinquire.我一感觉有疑问就随时咨询if作为连词的时候，一般用于条件状语从句也许是宾语从句或退步状语从句if指引的条件状语从句：Ifhecomes,pleasetellme.(假如，假如)主句和从句地点可以互换，时态：主将从现变为：Pleasetellme,ifhecomes.宾语从句中：Iwanttoknowif(能否)hecomes.可改成：Iwanttoknowwhetherhecomes.if句型的时态：主过从过主句一般此刻时，从句任何时客观真谛用一般此刻时退步状语从句中，if解说为即便名词cn.条件;假想Therearetoomanyifsinhisoffer.他的建议中条件太多了--------------------------------------------------------------------------------------。