新编英语教程第三版第二册unit.pdf

Unit3

ILead-in

IILanguageStructures

Modalauxiliaries

1.would+perfectinfinitiveusedto

express“unfulfilledwish”

.Iwouldhavelikedtosignup,butI

sprainedmyankle.

2.should/oughtto+perfectinfinitive

usedtoexpress“unfulfilled

obligation”

needn’t+perfectinfinitive

expressing“unnecessarypastactions”

.1)Sheshould/oughttohavehadmore

oralpracticeduringtheterm.

2)Sheneedn’thavelearnedallthe

dialoguesbyheart.

3.may/might+perfectinfinitiveused

toexpress“speculationsaboutpast

actions”

can/couldnot+perfectinfinitiveused

toexpress“negativedeductionabout

past

actions”

.1)Hemay/mighthavegonetothe

library.

2)Shecan’t/couldn’thavegoneto

thelibrary.

4.must+perfectinfinitiveusedto

express“affirmativedeductionabout

pastactions”

may/mightaswellusedwiththesecond

personpronounexpressing

“suggestions”

.1)Shemusthavegonetothelanguage

lab.

2)Youmay/mightaswellusemybike.

PreparatoryQuestions

Directions:Recastthefollowing

sentencesusingthefollowingphrases:

wouldhavelikedto(do)”

1.“

Notice:wouldhavelikedto(do)is

usedwiththefirstpersontoexpressthe

speaker’swishthatwa