新增语法项目：
if 和when的从句
现在进行时用于将要发生的事 过去进行时
与本级语言功能相关的情态单词，如：must, have to, need to, might 用于表示目的的不定式化 ( to do„ )式
语法解析
1.If ,when引导的条件句---第一条件句
If引导的条件句：if意为\"如果\"
If I am better tomorrow, I will get up.
If I have a headache, I will take an aspirin.If she finishes early, she will go home.
If it rains tomorrow, I\'ll go to school by bus.If it rains tomorrow, they won\'t go outside to play.
when引导的条件句，在此级别中意为\"要是，在„之后\" My mother came back when she finished her work.I will work in the garden when it stops raining.
2.过去进行时
形式：
过去进行时由was/were -ing 分词构成。
I was writing.
We were writing.用法：
①表示过去某时正在进行的动作。
What were you doing last night at seven o\'clock?
Workers were building a dam last summer.
②与always 连用表示过去经常重复的动作。
He was always changing his mind.She was always coming back late.
3.现在进行时用于将要发生的事 现在进行时可以表示正在发生的事情
The boys are playing football.那些男孩正在踢足球。 还可以表示将来时
They\'re leaving tomorrow.他们明天走 。
4.情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。 直接加动词原形
一、can, could
1) 表示能力（体力、知识、技能）。
Can you lift this heavy box?（体力）
2) 表示请求和允许。
-----Can I go now?
----- Yes, you can./ No, you can’t.
二、may 1) 表示请求和允许。 ---- May I smoke in this room?
三、must, have to
1) 表示必须、必要。
You must come in time.
2) must是说话人的主观看法， 而have to则强调客观需要。 1． He play isn’t interesting, I really must go now. 2． I had to work when I was your age.
四、need
1) need do sth。
1．You needn’t come so early. 2.---- Need I finish the work today? 3) need to do sth
1.He needs to finish his homework today.
五、will, would
1) 表示请求、建议等，would更委婉。
Will / Would you pa me the ball, please? 2) 表示意志、愿望和决心。
1.I will never do that again.
2.They asked him if he would go abroad.
六、should
1) should表示“应该”
1.I should help her because she is in trouble.
2) 表示劝告、建议和命令。should, ought to可通用，但在疑问句中常用should。
1.You should / ought to go to cla right away. 2.Should I open the window?
4.动词不定式表示目的 I came to see you.I study hard to become better.People have to work to make money.
5.进行时表示将来时(leave, go, come, fly, get back, set off…..) On the 1st day we are going sightseeing the Great Wall.On the 2nd day we are going the palace Museum and taking many beautiful photos.On the third day, we are going shopping and buying some food.We are getting back on the fourth day.I am setting off to HK to buy some fashionable clothes.He is coming to china tomorrow.I am leaving this place soon.
