八年级英语期中语法点大全

could的用法

I. could表示“可以;能”，是情态动词，其后应加动词原形;

II. could是can的过去式，表示过去的“能力”;

例：I could swim ten years ago.

III. 表示可能性，既表示现在的可能性，也表示过去的可能性，可能性比can弱;

例：Someone is knocking at the door. Who could it be?

IV. 用于有礼貌地提出请求建议，或请求许可。

例：Could I open the door? / Could you help me out?

2. should的用法

I. should表示“应该”，是情态动词，其后应加动词原形;

II. should用来提建议和忠告。

例：We middle school students should study hard.

III. should的否定形式为should not，可缩写为shouldn’t。

例：We should not/ shouldn’t spend too much time playing computer.

3. 用could, should来提建议

I. 陈述句

i. could在陈述句中用来委婉地陈述看法和建议，译为“不妨…”

例：You could turn to the teacher for help. 你不妨找老师帮忙。

ii. should在陈述句中表示比较肯定的忠告，译为“应该…”

例：You should turn to the teacher for help. 你应该找老师帮忙。

II. 疑问句

i. could用来委婉表达建议或请求许可，肯定答语用Yes,…can./ Sure，否定答语用No,…can’t/ Sorry。

—Could you please pass me the cup?

—Yes, I can./ Sure. (No, I can’t/ Sorry. )

ii. should只用于主语为第一人称的句子，表示征求意见或建议，语气比could更加委婉。

—Should I sit here?

—OK.

4. 动词短语

动词短语的类型有：

I. “动词 + 介词”

此类动词短语，作用相当于一个及物动词，后面必须带名词或动词ing

常见的有：look for, look after, wait for, hear from, listen to, depend on…

例：I’m looking for a job.

II. “动词 + 副词”

此类动词短语可以用作及物动词，也可用作不及物动词。

i. 用作及物动词时，后面必须带sb./ sth.。如果sb./ sth. 是名词，则放在动词之后或副词之后均可;但如果sb./ sth.是代词，则必须放在动词之后。

常见的这类短语有：cheer up, clean up, set up, put up, cut up, work out…

例：clean up the kitchen = clean the kitchen up/ clean it up

ii. 用作不及物动词时，不可以带sb./ sth.。

常见的这类短语有：start off, get up, come back, get down, get away

例：I get up early every morning.

III. “动词 + 副词 + 介词”

此类动词短语，作用相当于一个及物动词，后面必须带名词或动词ing

常见的有：look forward to, look down upon, come up with, do well in, run outof…

例：Never look down upon anyone.

IV. “动词 + 名词 + 介词”

此类动词短语，作用相当于一个及物动词，后面必须带名词

常见的有：make fun of, make use of, pay attention to, take care of, makefriends with…

例：In class, you should pay attention to your study.

V. “动词 + 形容词 + 介词”

此类动词短语，作用相当于一个及物动词，后面必须带名词

常见的有：be late for, be afraid of, be angry with, be busy with, be short for…

例：Bill is short for William.

5. 过去进行时

构成：sb. was/ were doing + 其它部分

用法：表示过去某一时刻或某一时间段之内正在发生的动作。

例：I was reading newspaper at 9:00 last night.

过去进行时的句子，常常以when或while引导的时间状语从句呈现。

when引导的从句中，动词可以是短暂性动词，也可以是延续性动词;时态可用一般态，也可以用进行态。

while引导的从句中，动词通常是延续性动词;时态用进行态。

例：I was doing the dishes when he came into the kitchen.

I was doing thehomework while my father was reading the magazine.