Autumn harvest is about to start.

4. 现在进行时

①表示说话时正在发生着的一个动作;表示现阶段但不一定是发生在讲话时;表近期特定的安排或计划;go、come等起止动作可用进行时代替将来时。如：

It is raining now.

He is teaching English and learning Chinese.

I am meeting Mr. Wang tonight.

We are leaving on Friday.

At six I am bathing the baby.(I start bathing the bady before six.)

The girl is always talking loud in public.(与always、often等频度副词连用，表经常反复的行动或某种感情色彩)

②下面四类动词不宜用现在进行时。(A)表示心理状态、情感的动作：like, love, hate, care, remember, believe, want, mind, wish, agree, mean, need。(B)表存在的状态的动词：appear, exist, lie, remain, seem belong to, depend on。(C)表示一时性动作的动词：allow, accept, permit, promise, admit, complete。(D)表示感官的动词：see, hear, notice, feel, smell, sound, taste, look。

5. 过去完成时

①常用过去完成时的几种情况：(A)在by、by the end、by the time、until、before、since后接表示过去某一时间的短语或从句以前发生的动作。如：By the end of last year, we had produced 20,000 cars. The train had left before we reached the station. (B)表示曾实现的希望、打算、意图、诺言等。常用had hoped / planned / meant / intended/

though / wanted / expected等或用上述动词过去式接不定式完成式表示即：hoped / planned … + to have done。(C)“时间名词 + before”在句子中作状语，谓语动词用过去完成时;“时间名词 + ago”在句中作状语，谓语动词用一般过去式。如：He said his first teacher had died at least 10 years before. Xiao Hua left school 3 years ago.(D)表示“一……就”的几个句型：Hardly / No sooner / Scarcely had + 主语 + 过去分词 + when / than / before + 一般过去时。如：We had no sooner been seated than the bus started. = No sooner had we been seated than the bus started.

②在before或after引导的时间状语从句中用一般过去时态代替过去完成时。

After he (had)left the room, the boss came in.

We arrived home before it snowed.

6. 过去将来时

参照一般将来时对比：用would do、was / were going to do sth.表过去将来;come、go、leave等过去进行时表过去将来时;was / were to do sth.和was / were about to do sth.表过去将来。

7. 过去进行时

①过去某一时刻正在进行的动作或某一阶段内发生或频繁发生。

②某一动作发生时另一动作正在发生，其中一个在由when或while引导的时间状语从句中。

8. 现在完成时

①现在完成时除可以和for、since引导的状语连用外，还可以和下面的介词短语连用：during / in /over the last(past)few years (months, weeks)、in recent years等。

②下列句型中常用现在完成时

It is (has been) + 一段时间 + since从句

This(That / It)is the first(second…)time that + 完成时

This(That / It)is the only … + that + 完成时

This(that / It)is the best / finest / most interesting … + that 从句 + 完成时

③在时间或条件状语从句中，现在完成时可以代替一般将来时。如：

I shall post the letter as soon as I have written it.

If you have done the experiment, you will realize the theory better.

Don’t get off the bus until it has stopped.

9. 时态区别

①一般过去时与现在完成时：时间上有差异：凡有过去时间的均用过去时态，不能用完成时态，如含有ago、last year、just now、the other day等。

结果上有差异：现在完成时强调的是对“现在”的影响和结果，动作到现在刚完成或还在继续;一般过去时强调的是动作发生在“过去”，和现在毫无关系。

②过去完成时与一般过去时：过去完成时强调的是“过去的过去”;如出现同一主语连续几个动作(“连谓”)形式则只用一般过去时即可。

2、被动语态考查要点简述

被动语态的构成方式：be + 过去分词，口语只也有用get / become + 过去分词表示。被动语态的基本用法：不知道或没必要提到动作的执行者是谁时用被动语态。强调或突出动作的承受者常用被动语态(by短语有时可以省略)。

(1)使用被动语态时应注意的几个问题。

①主动变化被动时双宾语的变化。看下列例句。

My friend gave me an interesting book on my birthday.

An interesting book was given to me(by my friend)on my birthday.

I was given an interesting book (by my friend)on my birthday.

②主动变被动时，宾补成主补(位置不变);(作补语的)不定式前需加to。

The boss made him work all day long.

He was made to work all day long(by the boss)

③短语动词变被动语态时，勿要掉“尾巴”。

The children were taken good care of (by her).

Your pronunciation and spelling should be paid attention to.

④情态动词和be going to、be to、be sure to、used to、have to、had better等结构变被动语态，只需将它们后面的动词原形变为be +过去分词。

⑤当句子的谓语为say、believe、expect、think、know、write、consider、report等时，被动语态有两种形式：(A)谓语动词用被动语态，动词不定式作主补。(B)用it作形式主语，真正的主语在后面用主语在后面用主语从句来表示。如：

People say he is a smart boy.

It is said that he is a smart boy.

He is said to be a smart boy.

People know paper was made in China first.

It is known that paper was made in China first.

Paper was known to be made in China first.

类似句型有：It is said / known / suggested / believed / hoped/ thought that …

(2)不能用被动语态的几种情况。

①所有的不及物动词或不及物动词词组不能用于被动语态之中。

②表示状态的谓语动词，如：last、hold、benefit、contain、equal、fit、join、mean、last、look like、consist to等。

③表示归属的动词，如have、own、belong to等。

④表示“希望、意图”的动词，如：wish、want、hope、like、love、hate等。

⑤宾语是反身代词或相互代词时谓语动词用主动语态，不能用被动语态。

⑥宾语是同源宾语，不定式、动名词等谓语动词不用被动语态。

⑦有些动词以其主动形式表示被动意义，特别是当主语是物时，常见的动词有sell、write、wash、open、lock等。