下面小编跟大家自考英语语法精讲分析，希望对大家的学习有所帮助。
语法部分
【情态动词】
情态动词具有一定的词义，没有人称和数的变化，不能单独充当谓语。它和谓语动词连用，表示“请求，愿望，建议，推测”等意义
这一节 交际
1．表示“请求”，请别人做事。用will, would, can, could。
句型：（1）Will /Would you（please）do … ？
（2）Can / Couldyou do … ?
在这两个句型中would, could比will, can更正式、客气。
Will / Would you please explain the textonce again ?
Can / Could you tell me what time Flight312 arrives?
2．询问是否“许可”。用can / could，may / might
句型：（1）May / Might Ido … ? （2）Can / Could Ido…?
在这两个句型中could, might比can, may更正式、客气。
—Could I use your car ?
—Yes, of course, you can ?（回答必须用can）
— Might I have a look at your new computer ?
— Yes, you may（回答必须用may）或Please goahead.
3．自己想做，要求对方做决定, 即征询对方意见。用shall，用于一、人称和第三人称。
句型：Shall I（we, he, she it, they）… ？译“要不要…？”
4．表示规劝，建议
1）正面的规劝，表示“好”，“应该”，或“必须”做某事。
①表示“好”，用had better，may / might as well或It is better / best to do sth.
②表示“有义务或有必要”，用should或ought to。即“应该”。
If you see anything unusual, you should call the police.
③用must 译：“必须”。
Theguide required that all passengers must wear seat belts.
导游要求所有旅客必须系安全带。
2）反面的规劝，表示“不必”，“不应当”，或“不许”做某事。
①表示“不必”，用needn’t 或 don’t have to 。
②表示“不应该”，用shouldn’t 或 oughtn’t to。
We shouldn’t throw cold water on them. 我们不应当给他们泼冷水。
③表示“不许”,用mustn’t。
needn’t /don’t have to → shouldn’t → mustn’t 语气逐步加强
5．须区别或注意的情态动词
1）can, could与be able to的区别
a）表示能力时can和be able to可以互换使用
I can / am able to speak English. She could / was able to read novels at ten.
b）表示在过去某一特定场合下，一次性表现出来的能力，只能用was / were able to。
The fire spread through the hotel veryquickly but everyone get out.
A．had to B．would C．could D．was able to（答案D）
2）shall用在主语是第二、第三人称的陈述句中，表示说话人给对方的许诺或命令。
Work hard and you shall be paid. 好好干，你会得到报酬的。（许诺）
You shall leave here at once. = You must leave here at once. （命令）
shall也用于法律、法令或规章等正式文件中，表示义务或规定。译“应，必须”。
The fine shall be paid in cash. 罚款应以现金交纳。
3）need和dare的用法。改错：
a）need（需要），dare（敢于）可作行为动词用，句型need to do, dare to do。也可作情态动词，但不能用在肯定句。在肯定句中只能作行为动词使用，故一、题B错，need → needs to；第二题C错，accept → to accept
b）need,作情态动词用时，无人称变化。need用于否定句和疑问句中；dare用于否定句、疑问句和条件句中。
4）should的用法。
should除表示“应该”外，还可用于表示情感、意志等句中的that从句。译“竟然、居然”。
第二节 推测
1．根据某一事实、现象推测可能发生的情况。用must, may, might。下表比较了三者表示推测肯定程度的差别，以及对不同情况推测的表达方式。
注：
1）must表示推测仅用于对当前和已发生的情况，不能用于推测将来可能发生的事情。must表示推测仅用于肯定句。在否定句和疑问句中，必须用can / could取代must。
2）may / might可以用于推测将来可能发生的情况，既可用于肯定句，也可用于否定句，但不能用于疑问句。在疑问句中，同样使用can / could。
2．根据经验或惯例对某一情况进行推测，用should或ought to，常译成“按理应该…”或“可能会……”。
It’s nearly seven o’clock. Jack should be here at any moment.
时间已将近7点了，按理Jack该回来了。
词组：
191. keep in touchwith保持联络Although he is abroad now, he can keep in touch with his friends by e-mail.192. keep off让……远离They made a big fire to keep wild animals off.193. keep on doing sth.重复地做某事Don't keep on asking silly questions.Keep on working for a whole day made me exhausted.194. keep one's balance保持平衡It's very important for an gymnastic to keep his/her balance.Keeping balance of nature is of great significance.195. keep one's promise遵守诺言no one will believe those who don't keep their promises.196. keep up振作精神；保持（习俗）；维持Keep up your spirits! Keep you chin up!Sometimes we should keep up old customs.How much does it cost you to keep up such a large house and garden? 197. knock at敲门Listen, I heard somebody knocking at the door.198. knock into sb.撞倒When I fell from the tree, I knocked into a passer-by.199. knock out of把……敲出来Grandfather was sitting at the table, knocking the ash out of his pipe.200. laugh at嘲笑Don't laugh at those who seem to be inferior.201. lay the table摆桌子Please lay the table. Dinner is ready.202. lead to 导致Carelessness led to the terrible traffic accident and death of five passengers.203. do one's lesson做功课You have to do your lesson before you can watch TV.204. have lesson上课We don't have any lessons on weekends.205. let in让……进入Windows let in light and air.These shoes let in water.Who let you in?
