ConditionalClauseMainclausepresentIf+subject+did/were

Subject+could/would/might/shoulddoGrammarpastIf+subject+haddoneSubject+could/would/might/shouldhavedoneConditionalClauseMainclauseConditionalClauseMainclausefuture

If+subject+did/should/weretoSubject+could/would/might/shoulddo

注：

Iftheconditionalclauseincludesauxiliaryverb(had,should,were)，wecanomittheword“if”,andthenputtheauxiliaryverbbeforethesubject.(inversion)

e.g.1)IfIwereatschoolagain,Iwould

workharder.

—WereIatschoolagain,I

would

workharder.

2)Ifyouhadfollowedthedoctor’s

advice,youwouldbequiteallright

now.

—Youwouldbequiteallrightnowhadyoufollowedthedoctor’sadvice.

3)Ifitshouldraintomorrow,Iwouldnotgothere.

—Shoulditraintomorrow,Iwouldnotgothere.

3.Intheobjectclausesoftheverbs“demand,order,require,request,propose,suggest,insist...”:

e.g.1)Hedemandedthatwe(should)

tellhimeverythingaboutit.2)Thechairmanproposedthat

we(should)discussthequestion.

3)Hesuggestedthatthesportsmeet(should)beputoffuntilMay.Compare：Hisaccentsuggestedthathewasfromthesouth.4)Theyinsistedthatthepaintings

(should)besoldathighprices.Compare：Heinsistedthathewasright.4.Intheadverbialclausesledby“asif/though”:e.g.1)Helooksasifhewereanartist.

—Infactheisn’tanartist.2)Itlooksasifitmightrain

—Thechanceofrainissmall.

Compare：

Itlooksasifitisgoingtorain.

—Itislikelytorain.3)Hetalkedasifhehadbeento

London.

—Infacthedidn’tgotoLondon.

5.Inthesentencetype“Itis(about,high)timethat...”:e.g.Itistimewewenttobed.6.Insimplesentencesexpressingone’swish:e.g.Mayyoubehappy!ConsolidationA.WhenSubjunctiveMoodisusedin

adverbialclauseofcondition,justremembertheform.B.SubjunctiveMoodwiththeverbinitsbaseform(do).Thesesituationsinclude:

a.Inthesubjectclausesofthesentencetype“Itisnatural(necessary,important,imperative,strange...)that...”

b.Intheobjectclausesoftheverbs

“demand,require,request,order,propose,insist,suggest,...”

c.Intheappositiveclausesofthenouns“demand,suggestion,order,proposal,recommendation,advice,resolution...”

e.g.Stevenshouldobeythedoctors’

advicethathe(should)haveasmalloperation.

d.Insimplesentencesexpressingone’swish.

e.Inadverbialclausesledbyconjunctions“incase,lest,forfearthat”

e.g.Thegameswillbepostponedlest

itshouldrain.C.SubjunctiveMoodwiththeverbinitspastorpastperfectform.Thesesituationsinclude:a.Intheobjectclausesoftheverb“wish”b.Intheadverbialclausesledby“asif/though”c.Inthesentencetype“Itis(about,high)timethat...”d.Inthesentencetype“Ifonly...”e.g.Ifonlysheknew/hadknownwheretofindyou.

e.Intheobjectc