ThePerfectUsagesofModalVerbs

Instructor:XXXXEmail:XXX@Note:microlectureon202X.XX.XXmodalverbexpressionoffeelingandattitudesnon-dependentverbnotensechangesLead-inTypes1musthavedone2can/couldhavedone3may/mighthavedone4should/oughttohavedone5needn’thavedonepresenttense:modalverb+verbspeculationonthecurrentsituationAperfecttense:modalverb+have+pastparticiplespeculationonthecurrentsituationBpresentandperfecttense(modalverb)Lead-inpresenttense:modalverb+verbspeculationonthecurrentsituationAperfecttense:modalverb+have+pastparticiplespeculationonthecurrentsituationBpresentandperfecttense(modalverb)Lead-inmodalverb+have+pastparticiple1musthavedonemusthavedone用于肯定句，表示對(duì)過去肯定的猜測(cè)，表示"過去一定做過某事"，是很有把握的推測(cè)。其否定形式為can't/couldn'thavedone。

Imusthaveseenyousomewhere,butIcan'trecollectyourname.我一定在哪個(gè)地方見過你，可我想不起你的名字了。Theroomisinaterriblemess;itcan'thavebeencleaned.房間里亂七八糟，一定沒打掃過。can/couldhavedone

是對(duì)過去本來能做而未做的事感到惋惜和遺憾，表示“可能、本來能夠做什么

”。Theoutputcouldhavebeenincreasedby15%.產(chǎn)量本可以提高15%的。2can/couldhavedonemay/mighthavedone對(duì)過去情況的一種不太有把握的推測(cè)，表示“過去可能已經(jīng)做了某事”；其否定形式表示為“過去可能還可沒有做某事”。HemayhavehadsometraininginChineseKungfu.他可能學(xué)過一點(diǎn)中國功夫。3may/mighthavedoneshould/oughttohavedone意為"本應(yīng)該……"，表示本應(yīng)該做某事，而實(shí)際沒有做，含有責(zé)備或遺憾的語氣。其否定形式為shouldnothavedone或oughtnottohavedone"本不該做某事"，表示某種行為不該發(fā)生但卻發(fā)生了。Theyoughttohavecompletedtheirworkmuchearlier.Youshouldn'thaveleftyoursonaloneathome.4should/oughttohavedoneneedn’thavedone

指沒必要做某事,實(shí)際上卻做了，表示"本不必做"。

Youneedn'thavewokenmeup;I