on condition (that)...引导的条件从句是主句事件发生的前提条件或唯一条件。
I can tell you the truth on condition that you promi to keep a cret.我可以告诉你真相，条件是你答应保守秘密。
You can go swimming on condition (that) you don't go too far from the river bank.你只有在不远离河岸的条件下才可以下水游泳。dell客服
3. supposing conj.如果，假如
supposing引导的条件从句表示一种假设条件。
Supposing it rains, shall we continue the sports meeting?倘若下雨，我们的运动会还要继续举行吗?
Supposing something should go wrong, what would you do then?假如出了什么问题，你准备怎么对付?
4. provided conj.假如，除非，以……为条件
provided (that) +从句表示一种假设条件。
He will sign the contract provided we offer more favorable terms.如果我们提出更优惠的条件，他就会在合同上签字。
He won't be against us in the meeting provided that we ask for his advice in advance.如果我们提前征求一下他的意见，他就不会在会上反对我们。
从上述例句可以看出if, unless, on condition (that), supposing, provided等词引导的条件状语从句，主从句条件关系分明，结构清晰。但有些句子，虽没有含条件关系的连词，却也隐含着条件关系，这些句子常用一些词，如but for, without等引出一个介词结构来表示条件，条件常常是虚拟的，或与事实相反的假设。如:
but for若非，要不是
But for the rain, we should have a pleasant journey.要不是下雨，我们的旅行肯定会很愉快。
表情简笔画
But for your help,we should not have finished in time.要不是你帮忙，我们肯定不能及时完成任务。
重点2 -if句
上个学期，我们曾经学过由if 引导的句子，你还记得吗？对了，“ I’ll not go to the zoo if it rains tomorr
ow. ( 假如明天下雨，我就不去动物园。) You can come to the party if you don’t wear jeans.（如果你不穿牛仔裤，你就能来舞会。）” 这个学期又在本单元见到了似曾相识的同样由if引导的句子，比如：“If I won the lottery, I would give it to medical rearch. （假如我赢了彩票的话，我就捐给医学研究。）If I were you, I would wear jeans and T-shirt.（如果我是你，我就穿牛仔裤和T恤。）”
这两个单元学到的句子都是由if引导的。那么，它们有什么区别呢？
分两种情况：
1．something may possible happen
某事发生的可能性较大。
这种情况，有个十三字口诀：“主将从现，主过将从过，主现从现”。即主句是一般将来时，从句用一般现在时；主句用过去将来时，从句用一般过去时；当主句中有can/can’t的话，则从句用一般现在时。例如：
If he has time, he will come tomorrow.
If she finishes early, she can come back early.
If you don’t do homework, the teacher will scold you.
Ⅰ.单项选择（15分）
1.If you _____ to the party, you’ll have a great time.
A. will go
B. went
C. go
D. going
正确佩戴口罩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?断桥相会
A. take
B. bring
C. carry
D. make
4. Weifang is famous ______ kites.
A. for
采桑子晏殊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 rain
B. rain
C. won’t rain
D. doesn’t rain
7.—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
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. will come
B. comes
C. is coming
D. came
11. There ____an English film in our school tomorrow.
A. is going to have
B. will have
C. is going to be
D. has
12. Could you tell us where ____？
A. will the next Olympic Games held
好看美女
B. the next Olympic Games will be held
C. would the next Olympic Games be held
D. the next Olympic Games would be held
13. When my mother returned last night, I ____ a book.
A. read
B. am reading
C. was reading
D. am going to read
14.What ____ you ____ when it began to rain?
A. do, do
B. were, doing
C. are, doing
D. did, do
15. I’ll wake you up when he ____back.
A. will
B. is going to come
C. comes
D. come
1---5 CDBAD 6---10 DAACB 11---15 CBCBC
I.选择最佳答案.
( ) 1.If it ______ sunny tomorrow, I ____ boating.
a. is go
b. will be, go
c. is, will go
d. will be, will go
( ) 2.----what will you do if it ______ tomorrow,
----I’ll stay at home and watch TV.
a. rain
b. rains
c. will rain
d. is raining
II. 同义句转换
1. Run fast, or you’ll be late for school.
_______ you _______ _______ fast, you’ll be late for school.
2. You can buy the dictionary if you take enough money with you.
Take enough money with you, ______ _____ ______ buy the dictionary.
3. If there is no air, none of us can live.
None of us can live _______ _________.
请将下列句子翻译成英语。
1. 如果明天有空，我和你一起参观十三陵。
_______________________________________________
2. 如果我们骑自行车去上班，我们可以避免空气污染。
______________________________________________
3. 如果你去青海湖，你将能看到青海湖自行车比赛。
_______________________________________________
4. 如果明天他不来，我会代替他去的。
_______________________________________________
.选择最佳答案.
( c ) 1.If it ______ sunny tomorrow, I ____ boating.
春天开的常见的花a. is go
b. will be, go
c. is, will go
d. will be, will go
( b ) 2.----what will you do if it ______ tomorrow,
----I’ll stay at home and watch TV.
a. rain
b. rains
c. will rain
d. is raining
II. 同义句转换
1. Run fast, or you’ll be late for school.
If you don't run fast, you’ll be late for school.
2. You can buy the dictionary if you take enough money with you.黄州寒食诗帖
Take enough money with you, and you can buy the dictionary.
3. If there is no air, none of us can live.
None of us can live without air.
请将下列句子翻译成英语。
1. 如果明天有空，我和你一起参观十三陵。
If I am free tomorrow,I will go to the Shisan mausoleum with you.
2. 如果我们骑自行车去上班，我们可以避免空气污染。
If we go to work by bike,we can prevent the air from polluting.
