正东方教育
初二上英语Unit 7
Memory
(广州最新版教材)
语法:Conditional sentences
条件句
Unit
7
Memory
Grammar
Conditional sentences
条件句
Part One
if条件句
在本单元的Grammar板块,我们将学习另一种if条件句,并复习我们在七年级上册中已经学习过的if条件句。
1条件句(1)
请看下面的例子: If从句(一般现在时)+主句(一般现在时)
If you cool steam, it turns into water.
这句句子所表达的含义是:Every time you cool steam,it turns into
water.
我们用“if从句(一般现在时)+主句(一般现在时)”的条件句来表达真理或事实。
又如:
If we don't water a flower, it dies. (=Every time we don't water a
flower, it dies.)
如果我们不浇花,它就会枯死。
If you drop a vase,it breaks.如果你把花瓶摔了,它就会碎。
主句也可以放在if从句前,这时两个分句间没有逗号(,)。如:
Ice
becomes water if you heat it.如果给冰加热,冰就会变成水。
2
条件句(2)
在七年级上册第六单元的Grammar板块中,我们已经学习了结构为“主句用一般将来时,if从句用一般现在时”
的if条件句来谈论可能发生的事件。从句部分的一般现在时用于表述将来可能发生的动作或情况,主句部分的一般将未时表述条件成立时可能产生的结果。
If条件状语从句的构成:
1.
If you ask him, he will help
you.如果你请他帮忙,他会帮你的。
↓
↓
(从句)
(主句)
2.
Print the photo if you like
it.
如果喜欢这张照片就把他打印出来。
↓
↓
(主句)
(从句)
▲If:从属连词,意思是:“如果,假如,倘若”
If从句的位置:
if
引导的条件状语从句既可以放在主句前,也可以放在主句后。从句位于主句之前时,常用逗号与其隔开。
If
从句(一般现在时)+主句(一般将来时)
If we don’t hurry, we won’t finish the work on
time.
If we go by bus,it will be cheaper.
If you don't hurry, you’ll miss the train.
If
I like the house, I will buy it.
如果我喜欢这房子,我就会把它买下
I will tell her if I see
her. 如果我见到她,我就会告诉她。
我们同样可以将if从句放在主句后。
You’ll miss the train if you don't
hurry.
It will be cheaper if we go by bus.
这类if条件句的主句部分还可以用祈使句。如:
If it's cold later tonight,take your coat with
you.
Don't wait for me if I'm late.
这类if条件句的主句部分还可以用情态动词。如:
I
may buy a car if I pass my driving test.
If
you go to another country,you must obey the local
laws.
If
they are friendly,I might invite them to the
party.
如果他们很友善,我可能会请他们去参加聚会
If
we hurry now, we can stop for coffee
later.
如果我们现在抓紧时间,就可以稍后去喝咖啡
Part
Two
if…not与unless的用法
1
连词unless意为“除非……(否则)”,用来引导否定意义的条件句。
unless引导条件句时,主要用于下列情况:
(1)主句为肯定句。如:
You will miss the bus unless you hurry up.
You'll fail your Chemistry test again unless you work
harder.
(2)主句为否定句或含有表示否定意义的词。如:
Unless you are
friendly to people, you won't get on well with
them.(与人相处得好)
You
will never get anywhere unless you set your
goal.
Unless I visit
every bookstore in town, I won’t buy this
book.
Unless you work hard, you won’t pass the exam.
2
unless在意义上可以理解为if…not,在有些情况下两者可以互换使用。如:
I
can't see unless I wear glasses. (=I can't see if I don't wear
glasses.)
Unless you can pay
your bills, you’ll have to leave. (=If you can't pay your bills,
you’ll have to leave.)
从上面的例子可以看出,由于unless已经表达了if…not的含义,它所引导的条件状语从句只能使用肯定形式。
Part Three
知识拓展
1. 在以when,before,as soon
as等引导的时间状语从句,也适用“主将从现”原则,即如果主句是一般将来时,从句则用一般现在时。
I'll tell her the good news when she comes
back.当她回来的时候,我将把这个好消息告诉她。
She will give you a call as
soon as she returns.她一回来就会给你电话。
2. If条件句==祈使句,and
/or+将来时态的陈述句。<同义句转换>
Work hard, and you
will make great progress.
=If you work hard,
you will make great progress.
如果你努力学习,你才会取得大的进步。
Hurry up, or you
will be late. =If you don’t hurry up, you will be
late.
如果你不快点,你就要迟到了。
语法针对练习
考题形式
1.考时态:主现从现;
主将从现,主祈从现,主情从现
“四大原则”
考法:
可能已知主句,考从句用一般现在时
可能已知从句,考主句用一般将来时
2.
考从句引导词if或unless
<从含义入手即可,if意为“如果”
unless意为“除非...(否则...)”
3.
考拓展 when, as soon as,
before等引导的时间状语从句,也可以使用“主将从现”
语法针对练习
一、
Join the sentences with
if.
1.
The temperature rises t0
100℃.
The
room becomes bright.
2.
You feel
cool.
It
rains.
3.
You switch on the
lights.
Water
boils,
4.
The ground gets
wet.
You
turn on the air conditioner.
5.
You put oil on
water.
You add 5 and 3,
6.
You get
8.
It floats.
1.
_______________________________________________________________________
2.
_______________________________________________________________________
3.
_______________________________________________________________________
4.
_______________________________________________________________________
5.
_______________________________________________________________________
6.
_______________________________________________________________________
二、
Put these facts into conditional sentences with
if.
1.
例题: Doctors treat sick people.
If you're a doctor, you treat sick people.
2.
Vegetarians don't eat meat.
If you're a vegetarian,
______________________________________________
.
3.
People in a hot country don't like cold
weather.
If you
live______________________________________________________________.
4.
Dancers have to be tall and slim.
If you're a dancer,
_______________________________________________________.
5.
Mechanics understand engines.
If you're
a______________________________________________________________.
三、
用括号中所给动词的正确时态完成下列句子.
1.
If ________________ (it/rain), _________________ (we/not/go) out.
We'll stay at home.
2.
If ________________ (the weather/be) nice tomorrow,
_________________ (we/drive) to the coast.
3.
If __________________ (she post) the letter now, _________________
(they/receive) it tomorrow.
4.
________________ (Fiona/be) angry if ________________ (John/arrive)
here late again.
5.
________________ (I/go) to their party if _________________
(I/have) enough time.
6.
Unless ________________ (she/pass) this exam, ________________
(she/not/get) this job.
7.
________________ (you/learn) a lot if ________________ (you/take)
this course. '
8.
If _________________ (I/get) a ticket, ________________ (I/go) to
the concert.
9.
________________ (I/buy) that camera unless ________________
(it/cost) too much.
10.
If ________________ (you/run) very fast, ________________
(you/catch) the bus.
11.
________________ (I/go) to see the doctor if ________________
(I/not/feel) better tomorrow.
12.
If _________________ (they/win) this game, ________________
(they/be) the champion.
13.
If __________ (you/get) on the train, just _____________ (relax)
along the way for the whole journey.
14.
If________________ (you/live) in England, ________________
(not/forget) to drive on the left!
四、
根据流程图,给主句选出一个搭配的从句,并打钩。
early>catch bus>on time
for work>manager pleased>get a pay rise
get up late>miss
bus>late for work>manager angry>lose
job
a)
If you get up early
|
you'll miss the
bus.
|
b)
Unless you get up early,
|
|
a)
If you catch the bus,
|
you'll be on time
for work.
|
b)
Unless you catch the bus,
|
|
a)
If you are on time for work,
|
your
manager will be angry.
|
b)
Unless you are on time for work,
|
|
a)
If your manager isn't pleased with you,
|
you'll lose your
job.
|
b)
Unless your manager is angry with you,
|
|
a)
If your manager is pleased with you,
|
you
won't get a pay rise.
|
b)
Unless your manager is pleased with you,
|
根据上题中的流程图,完成句子。
1
You won’t catch the bus
unless________________________________________________
2
You will catch the bus
unless________________________________________________
3
You will be late for work
unless________________________________________________
4
Your manager won’t be pleased with you
unless______________________________________
5
You won’t lose your job
unless________________________________________________
6
You will get a pay rise
unless________________________________________________
7
Unless you want to lose your job,
________________________________________________
五、
根据括号中的提示,用unless完成句子。
1
You won’t get there on time
________________________________________________(hurry).
2
We can’t have a
picnic________________________________________________(it, a nice
day).
3
Don’t leave the TV on
________________________________________________(watch
it).
4
We can’t do the
job________________________________________________(get some
help).
5
I won’t buy the
picture________________________________________________ (like
it).
六、
Complete the sentence with if or
unless.
1
Rachel will be pleased ________________she passes her driving
test.
2
The bus won’t stop___________________ you ring the
bell.
3
I can’t read your writing __________________you print it
clearly.
4
Emma will e upset __________she doesn’t get the
job.
5
You can’t go inside the cinema_________________ you get a
ticket.
6
Don’t bother(打扰)to ring me ________________you have something
important.
七、
选择正确答案。
1.
--Will you go to David's wedding party?
--I won't go _________I am
invited.
A.
because
B.
and
C.
but
D. unless
2.
If you_________ the water, it _________ into
gas.
A. boil;
turns B.
boil; will
turns
C. will boil;
turn
D. will boil; will turn
3.
I_________ you if I_________ free tomorrow.
A. visit; will
be
B. will visit; will
be
C. will visit,
am
D. visit, am
4.
_________you have lots of money, you can't buy that
house.
A.
If
B.
Because
C.
Unless
D. Until
5.
You will fail the exam _________ you don't study
hard.
A. and
B.
though
C.
but
D. if
6.
You won't learn English well _________you work
hard.
A.
unless
B.
when
C.
if
D. because
7.
_________you don't go to bed earlier, you will feel tired
tomorrow.
A.
Unless
B.
If
C.
Though
D. Until
8.
I won't come to see you _________I am asked to.
A.
unless
B.
because
C.
if
D. though
9.
I won't leave here until he _________back.
A.
come
B.
comes
C. will come
D. came
10.
-Would you like to go shopping with us
tomorrow?
-Sure, _________I am busy.
A.
since
B.
unless
C.
when
D. until
11.
She will come to help us if she _________ too busy
tomorrow.
A.
is
B.
isn't
C. will
be
D. won't be
12.
--There will be a baseball match this Sunday. Would you like to go
with me?
--If I have time, I _________with you.
A.
went
B. will
go
C.
go
D. have watched
13.
If I find his phone number, I _________ you.
A.
tell
B.
told
C. will
tell
D. have told
14.
You'd better look up the new word in a dictionary ______ you don't
know it.
A.
if
B.
that
C.
though
D. whether
15.
Don't talk loudly at the meeting. If you __________, you will have
to leave.
A.
are
B.
do
C.
did
D. can
16.
--The art club is for members only. You can't go in_________ you
are a member.
A.
unless
B.
because
C.
if
D. though
17.
--Why were you late again?
--_________ I missed the bus.
A.
Unless
B.
If
C.
Because
D. When
18.
I'm waiting for my friend. _________, I'll go shopping
alone.
A.
If she
comes
B.
If she will come
C.
If she doesn't come
D.
If she didn't come
19.
--Mum, my tooth hurts so much.
--If you_________ too many sweets, you_________
better.
A.
eat;
feel
B. stop eating; will feel
C.
will eat;
feel
D. don't eat; feel
20.
--Dad, can I have another cake?
--Yes, you can _________ you are afraid of_________
fat.
A.
unless;
getting
B. if;
get
C.
if;
getting
B. unless; get
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