内容正文:
Lesson 2 Grammar Focus
语法练习
I think I'll take the bus to the party.
If you do,you'll be late.
I think I'll stay at home.
If you do,you'll be sorry.
What will happen if they have the party today
If they have it today,half the class won't come.
If we ask people to bring food,they'll just bring potato chips and
Should we ask people to bring food
chocolate.
语法详解
if引导的条件状语从句和情态动词should
一、f引导的条件状语从句
定义:条件状语从句是表示主句动作发生的前提或条件的从句。即“在条件下某事才能发生”。通常由连词f引导。
位置:f引导的条件状语从句可位干主句之前或之后。位干主句之前要用逗号与主句隔开:如果放在主句之后。其前不必用逗号。
时态:若主句为一般将来时、祈使句,或主句含有can,may,must,have to等情态动词或短语时.if引导的条件状语从句要用一般现在时。如:
If it is sunny tomorrow,I will go fishing.=I will go fishing if it is sunny tomorrow.
如果明天天气睛朗,我将去钓鱼。
Hurry up if you don't want to be late for school.
如果你不想上学迟到就快点。
You can win the game if you practice hard.
如果你刻苦练习,你会赢得比赛的。
★f引导的条件状语从句,通常可与以下句型相互转换:
◆祈使句+and/or+一般将来时的句子
If you run fast,you will catch up with others.如果你跑快点,你会追上其他人的。
=Run fast,and you will catch up with others.跑快点,你会追上其他人的。
=Run fast,or you won't catch up with others.跑快点,否则你追不上其他人a
◆含有介词wth或without的句子
If there is no air,we can't live.=We can't live without air.
(如果)没有空气,我们无法生存。
注意:f除可引导条件状语从句外,还可引导宾语从句,意为“是否”。
I don't know if they will come back tomorrow.
我不知道他们明天是否回来。
二、情态动词should
should为情态动词。后接动词原形,其句式及主要用法如下:
句式
用法
例句
主语+should+动词原形+其他.
肯定句式
You should come here earlier.
主语+shouldn't十动词原形+其他.
否定句式
I shouldn't tell you the news.
一般疑问句式
Should+主语+动词原形十其他?
Should I help Tim finish the work
should的用法:
◆表示义务、职责等,意为"应该。如:We should follow the school rules.我们应该遵守校规。
◆表示推测,意为“按道理说应该会”。如:
Other students should be there by now.现在其他学生应该在那儿了。
◆用于提出建议或要求对方给出意见。如:
You should finish your homework first..你应该先完成你的作业。
综合练习
一、用所给单词的适当形式填空
1.If you(come)to the zoo,you
(have)a good time.
2.I don't know if it (is)sunny tomorrow.
3.If it_(is)sunny,we can(go)out to play.
4.(put)up your coat,if it(rain)tomorrow.
5.We should (be)quiet in the library.
二、按要求完成句子
l.We can't live without water.(同义句转换)
If there is water,we live.
2.Work hard,and you will pas