if引導的條件狀語從句和賓語從句11

第頁If的用法if的條件從句分為真實條件從句和虛擬條件從句。真實條件從句：真實條件從句適用于主將從現(xiàn)，是假設(shè)有可能發(fā)生的。位置在if

引導的條件狀語從句中，既可以放在主句之前，也可以放在主句之后。若if

條件句放句首，從句后面要加逗號，和主句隔開。Youwillcatchthebusifyougetupearly.=Ifyougetupearly,youwillcatchthebus.時態(tài)1.（主祈從現(xiàn)）主句：一般現(xiàn)在時態(tài)（包含祈使句和含有情態(tài)動詞can,may,must等的句子）從句：一般現(xiàn)在時態(tài)2.（主將從現(xiàn)）主句：一般將來時態(tài)從句：一般現(xiàn)在時態(tài)3.從句:現(xiàn)在進行時，主句:一般將來時

If

you

are

looking

for

Peter

you’ll

find

him

upstairs.

如果你是在找彼得，上樓就會找到他。

4．if從句用現(xiàn)在完成時，主句用一般將來時

If

you

have

finished

dinner

I’ll

ask

the

waiter

for

the

bill.

如果你吃完了，我就叫服務生來算賬5.if

條件句談論的是重復發(fā)生和預示要發(fā)生的情景和事件，則主從句大多用一般現(xiàn)在時態(tài)。如：If

bears

are

in

danger

,they

attack

people.

注意事項在if引導的條件狀語從句中，當主句是一般將來時態(tài)時，不能使用begoingto結(jié)構(gòu)，而要用will.在if引導的條件狀語從句中,不能使用some,而要用any.同義句轉(zhuǎn)化借助于祈使句+and∕or+簡單句轉(zhuǎn)化，and表示順承，or表示轉(zhuǎn)折。例如：(1)Ifyouworkhard,you’ll

passtheexam.Workhard,andyou’llpasstheexam.(2)Ifyoudon’thurryup,you’llbelate.Hurryup,oryou’llbelate.借助于介詞with或者without來轉(zhuǎn)換例如：Ifyouhelpme,I’llfinishmyjobsoon.Withyourhelp,I’llfinishmyjobsoon.if

條件句不一般,幾個要點記心間條件句,放在前,逗號要放句中間。條件句表可能，主句多用將來時；條件句表事實，主句常用現(xiàn)在時。虛擬條件從句:虛擬條件從句是假設(shè)不太可能發(fā)生的。

IF的虛擬語氣有三種：

內(nèi)容從句主句

及現(xiàn)在事實相反動詞過去式（be用were）would/could/should/might+動原

及將來事實相反should/wereto+動原would/could/should/might+動原及過去事實相反had+過分would/could/should/might+have+過分

下面三句依次是上面三種情況的例句：

IfIwereyou,Iwould/could/should/mightdothat.

IfIhadknowthatyesterday,Iwould/could/should/mighthavetoldyou.

Ifitshouldrain,thecropswould/could/mightbesaved.

If引導的賓語從句一．if引導賓語從句時，意思為：是否，從句的時態(tài)通常要和主句保持一致。【例句】Iwanttoknowifhelivesthere.我想知道他是否住在那兒。HeaskedmeifIcouldhelphim.他問我是否能幫他?！究疾辄c】if、whether引導的賓語從句的區(qū)別1.if或whether引導賓語從句時，作“是否”講，常放在動詞ask、see、say、know和findout等后面。一般情況下，兩者?？蓳Q用，在口語中多用if。【例句】Nobodyknowswhether/ifitwillraintomorrow.沒有人知道明天是否下雨。Lucyaskedwhether/iftheyhadacottonsweater.露西問他們是否有棉制的毛衣。二.注意事項：if或whether引導賓語從句時，要注意三個方面，即連詞、語序和時態(tài)。1.if或whether既不能和that或其他連詞（副詞）同時使用，也不能省略。【例句】我不知道他今天是否會來。[誤]Idon’tknowthatif(whether)hewillcomeheretoday.[正]Idon’tknowif(whether)hewillcomeheretoday.他走過來看看貓是否出了毛病。[誤]Hecametoseewhatif(whether)therewasanythingwrongwithhiscat.[正]Hecametoseeif(whether)therewasanythingwrongwithhiscat.2.if或whether引導賓語從句時，雖具有疑問的意義，但其從句應用陳述句的語序。【例句】Didyouknowthewaytothehospital?Theoldwomanaskedme.Theoldwomanaskedmeif/whetherIknewthewaytothehospital.老婦人問我是否知道去醫(yī)院的路。if或whether引導的賓語從句應和主句的時態(tài)保持一致。即主句為一般現(xiàn)在時，從句用任一種時態(tài)；主句為一般過去時，從句則用過去時中的任一種時態(tài)?！纠洹縄don’tknowif(whether)hehascomehere.我不知道他是否來過這兒。Tomaskedif(whether)Ihadreadthebook.湯姆問我是否看過這本書。三．If和whether兩者不能互換的情況1.只能用whether的情況在動詞不定式之前只能用whether：【例句】Ican’tdecidewhethertostay.我不能決定是否留下。2.在whether…ornot的固定搭配中：【例句】Iwanttoknowwhetherit’sgoodnewsornot.我想知道它是不是好消息。3.在介詞后，只能用whether：【例句】Hisfatherisworriedaboutwhetherheloseshiswork.他的父親擔心他是否會失去工作。4.用if會引起歧義時：【例句】Couldyoutellmeifyouknowtheanswer?這句話有兩種意思：“你能告訴我你是否知道答案嗎？”或“如果你知道答案，請告訴我，好嗎？”。如用whether則可避免歧義?！究碱}鏈接】Idon’tknow_________theycouldpasstheexamornot.A.whyB.ifC.thatD.whether答案：D解題思路：本題考查if及whether的區(qū)別，在whether…ornot的固定搭配中通常只用whether。練習題：句型轉(zhuǎn)換1.Dotheywantfriedchicken?Heaskedtheboys.(改為賓語從句)Heaskedtheboys_______they______friedchicken.2.WasthewatchmadeinShanghai?Idon’tknow.(改為賓語從句)Idon’tknow_______thewatch_______madeinShanghai.3.“Doyouwanttotrysomethingnew?”Tom’smotheraskedhim.(同義句轉(zhuǎn)換)Tom’smotheraskedhim_____________________totrysomethingnew.答案：1.if/whether,wanted2.if/whether,was3.if/whetherhewanted一、用所給詞的適當形式填空1.If

you

________(feel)

tired,

you

_______________

(have)

to

have

a

rest.

3.

If

there

__________(be)

fewer

trees,

there

_______________(

be)

more

pollution.

5.

If

Marcia

_____________(live)

alone,

she

___________________(

keep)

a

pet

parrot.

6.

Lana

________________(

buy)

a

new

dress

if

the

old

one

____________(be)

out

of

style.

9.

Peter

_____________(

send)

me

a

beautiful

souvenir

if

he

________________(tour)

Spain.

10.

If

Mr

Green

___________(say)

I

am

hard-

working,

my

parents

_________(

feel)

glad.

11.I

____________(go)

to

the

beach

if

it________________

(

not

rain)

this

week.

13.He

____(write)

a

letter

to

his

grandparents

if

he

____(get)

his

report

card

this

week.

14.

If

she

____________(get)

up

late,

she

_____________

(

not

catch)

the

early

bus.

15.

Peter

________(major)

in

English

if

he

____(pass)

the

exams

in

Peking

University.

16.

如果努力學習，你就會取得好成績。

If

you__________

_________,

you

___________

good

_____________.

17.

他如果看電視太久了，他的父母會不高興。

If

he

_________

TV

too

much,

his

parents

__________

__________

unhappy.

18.

如果我們?yōu)樗M織生日聚會，大家都會來的。

Everyone

________________

if

we

_____________

a

birthday

party

__________

him.

19.

如果明天不下雨，我會和你一起去公園的。

If

it

__________

__________

tomorrow,

I

______________

go

to

the

park

_________

you.

21.

如果他有空，他會幫助你的。If

he

_________________,

he

_________________

you.

23.

你如果抄同學的作業(yè)就不能學好各門功課。

You

_______

_____

good

at

all

the

subjects

if

you

______

the

other

students’

homework.

Ⅰ單項選擇（1.If

you

_____

to

the

party,

you’ll

have

a

great

time.

A.

will

go

B.

went

C.

go

D.

going

2.

It

will

be

a

long

time

____

Peter

_____

his

work.

A.

since,

has

finished

B.

after,

finishes

C.

when,

will

finish

D.

before,

finishes.

3.

What

will

father

_____

us

from

Japan?

A.

take

B.

bring

C.

carry

D.

make

4.

Weifang

is

famous

______

kites.A.

for

B.

to

C.

on

D.

with

5．I

____

her

the

answer

if

she

____me.

A.

can

tell,

will

ask

B.

will

tell,

will

ask

C.

would

tell,

ask

D.

will

tell,

asks

6.

–

What

are

you

going

to

do

tomorrow?

--We’ll

go

to

the

library

tomorrow

if

it

___.

A.

isn’t

rainB.

rain

C.

won’t

rainD.

doesn’t

rain7.—Do

you

know

when

he

will

come

back

tomorrow?

--Sorry,

I

don’t

know.

When

he

____

back,

I’ll

tell

you.

A.

comes

B.

will

come

C.

come

D.

may

come

8.

What

will

you

do

if

you

_____

to

the

old

folk’s

home

visit?

A.

go

B.

went

C.going

D.

will

go

9.

If

I

eat

____

food,

I’ll

be

very

fat.

A.

too

many

B.

many

too

C.

too

much

D.

much

too

10.

I’ll

give

the

book

to

him

if

he

___

here

next

Sunday.

A.

w