虛擬語氣的定義虛擬語氣是謂語動詞的一種特殊形式，用來表示說話人的主觀愿望,假想、猜測、建議、可能或純粹的空想等非真實情況,所說的是一個條件,不一定是事實,或與事實相反。在條件句中的應用

條件句可分為兩類,一類為真實條件句,一類為非真實條件句。非真實條件句是相對于真實條件句而言的。我們以前所學的條件狀語從句都是屬于真實條件句。非真實條件句表示的是假設的或實際可能性不大的情況，故采用虛擬語氣非真實條件句的分類：一.

與現在事實相反；二.

與過去事實相反；三.

與將來事實可能相反。虛擬語氣在條件句中的應用

現在

過去式;werewould/shouldcould/might+動詞原形

過去

had+過去分詞would/shouldcould/might+have+過去分詞

將來過去式should+動詞原形wereto+動詞原形would/shouldcould/might+動詞原形1真實條件句真實條件句用于陳述語氣，假設的情況可能發生，其中if是如果的意思。 (時態關系)

條件從句 主句

一般現在時 shall/will+動詞原形

Ifhecomes,hewillbringhisviolin.

典型例題

Thevolleyballmatchwillbeputoffifit___.

A.

willrain

B.rains

C.rained

D.israined

1.在真實條件句中,主句不能用begoingto表示將來,該用shall,will.

(錯)Ifyouleavenow,youarenevergoingtoregretit.

(對)Ifyouleavenow,youwillneverregretit.

2.表示真理時，主句謂語動詞便不用shall(will)+動詞原形，而直接用一般現在時的動詞形式。表示與過去事實相反的假設。從句的謂語用had+過去分詞,主句的謂語用would(should,could,might)

have+

過去分詞。條件從句 主句

過去完成時should(would,could,might)have+過去分詞

Ifshehadworkedharder,shewouldhavesucceeded.

Thericewouldnothavebeenburntifyouhadbeenmorecareful.

IfmylawyerhadbeenherelastSaturday,hewouldhavepreventedmefromgoing.

Ifhehadcomeyesterday,Ishould/wouldhavetoldhimaboutit.

含義：Hedidnotcomeyesterday,soIdidnottellhimaboutit.

Ifhehadnotbeenillandmissedmanyclasses,hewouldhavemadegreaterprogress.

含義：Hewasillandmissedmanylessons,sohedidnotmakegreaterprogress.

If

you

had

previewed

the

text,

you

wouldn’t

havefailed

to

answer

the

question.如果你有預習課文的話，你就不至于不會回答這個問題。She

would

have

come

if

she

hadn’t

been

so

busy.如果她不是這么忙的話，她早就來了。c.表示對將來的假想

從句的謂語用動詞過去式/should

+動詞原形/或were

to

+

動詞原形;主句的謂語用would(should,

could,

might)+

動詞原形。 條件從句主句

一般過去時should+動詞原形

were+不定式would+動詞原形

should+動詞原形Ifyousucceeded,everythingwouldbeallright.Ifyoushouldsucceed,everythingwouldbeallright.Ifyouweretosucceed,everythingwouldbeallright.If

it

were

Sunday

tomorrow,

I

should

go

to

seethe

film.如果明天是星期天的話,我就會去看電影.（實際上，明天不是星期天。）If

she

should

come,

I

would

ask

her

for

help.如果她會來，我就會請求她的幫助。If

I

were

to

do

it,

I

would

do

it

in

a

different

way.要是我來做這件事，我會用不同的方式來做。Should

there

be

a

flood,

what

should

we

do?萬一發生了水災，我們該怎么辦呢？

Were

it

not

for

their

assistance,

we

would

be

in

serious

difficulty.要是沒有他們的幫助，我們會陷入困境。

Had

you

arrived

at

the

station

ten

minutes

earlier,

you

could

have

caught

the

train.如果你早十分鐘到達車站的話，你早就趕上火車了。混合條件句主句與從句的動作發生在不同的時間，這時主，從句謂語動詞的虛擬語氣形式因時間不同而不同，這叫做混合條件句。

Ifyouhadaskedhimyesterday,youwouldknowwhattodonow.

（從句與過去事實相反，主句與現在事實相反。）

Ifithadrainedlastnight(過去),itwouldbeverycoldtoday(現在).虛擬語氣---主語從句形容詞為necessary,

important,

impossible,

strange,

natural,

essential時，在“It

+

be

+

形容詞或過去分詞

+

主語從句”中，Itisdemanded/apity+that…結構中的主語從句的謂語動詞要用虛擬,should加動詞原形，should可省略。It

is

necessary

that

the

problem

(should)

be

discussed

at

once.立刻討論這個問題很有必要。It

is

strange

that

he

(should)

have

so

many

friends.太奇怪了，他有那么多的朋友。It

has

been

decided

that

the

meeting

(should)

be

put

off.已經決定推遲這個會議。(1)suggested

Itis

(2)important

that…+(should)do

(3)apity

(1)suggested,ordered,proposed,required,demanded,requested,insisted,advice+(should)do

(2)important,necessary,natural,strange

apity,

ashame,

nowonder

(3)Itissuggestedthatwe(should)holdameetingnextweek.

Itisnecessarythathe(should)cometoourmeetingtomorrow.賓語從句一些含有假設、猜想、建議等意思的動詞后面的賓語從句要用should+原形動詞結構,should往往可以省略。這類動詞有:advice,

arrange,

command,

demand,

desire,

insist,

order,

propose,

require,

request,

suggest等 +(should)doI

suggested

that

he

study

harder.我建議他用功一些。I

insisted

that

he

(should)

go.我強調他應當去。She

commanded

that

we

(should)

attack

at

once.她命令我們必須立刻進攻。I

demand

that

John

go

there

at

once.我要求約翰必須立刻到那兒去。Isuggestthatwe(should)holdameetingnextweek.

Heinsistedthathe(should)besentthere.

注意：如suggest,insist不表示“建議”或“堅持要某人做某事時”，即它們用于其本意“暗示、表明”、“堅持認為”時，賓語從句用陳述語氣。

Theguardatgateinsistedthateverybodyobeytherules.

(F)Yourpalefacesuggeststhatyou(should)beill.

(R)Yourpalefacesuggeststhatyouareill.

(F)Iinsistedthatyou(should)bewrong.

(R)Iinsistedthatyouwerewrong.在表語從句，同位語從句中的應用

主語是suggestion,proposal,notion,idea,plan,request,order,advice等名詞后面的表語從句、同位語從句中要用虛擬語氣，即（should）+動詞原形。

Myideaisthatwe(should)getmorepeopletoattendtheconference.

Imakeaproposalthatwe(should)holdameetingnextweek.My

suggestion

is

that

we

(should)

go

and

help

him.我的建議是我們應該去幫助他。Our

only

request

is

that

this

should

be

settled

as

soon

as

possible.我們唯一的請求就是盡快解決這個問題。比較ifonly與onlyifonlyif表示“只有”；ifonly則表示“如果……就好了”。Ifonly也可用于陳述語氣。

Iwakeuponlyifthealarmclockrings.

只有鬧鐘響了，我才會醒。

Ifonlythealarmclockhadrung.

當時鬧鐘響了，就好了。Ifonlyhecomesearly.但愿他早點回來。Itis(high)timethatItis(high)timethat后面的從句謂語動詞要用過去式或用should加動詞原形，但should不可省略。

Itistimethatthechildrenwenttobed.

Itishightimethatthechildrenshouldgotobed.need"不必做"和"本不該做"didn‘tneedtodo表示;過去不必做某事,事實上也沒做。.

needn’thavedone表示;過去不必做某事,但事實上做了.

JohnwenttothestationwiththecartomeetMary,soshedidn‘tneedtowalkbackhome.約翰開車去車站接瑪麗，所以她不必步行回