语法结构——时 态（时态上）
一般现在时表示现在、经常或习惯的动作或状态和普遍现象、常识或客观真理；一般过去时用于过去某一时间内发生的或过去习惯性的动作或状态；一般将来时表示将要发生的动作或存在的状态，将来打算做的事情；现在完成时表示过去发生的动作造成目前的结果和对现在造成的影响或表示从过去延续至今的动作、状态和习惯等；将来完成时表示将来某时之前业已完成或发生的事情；过去完成时表示过去某时间之前已经发生的动作或状况，即过去的过去。注意每一种时态与其他时态的交叉使用情况。英语共有十六种时态，其表现形式如下（以study为例）：
一般时进行时完成时完成进行时现在study
studiesam studying
is studying
are studyinghave studied
has studiedhave been studying
has been studying过去studiedwas studying
were studyinghad studiedhad been studying将来shall study
will studyshall be studying
will be studyingshall have studied
will have studiedshall have been studying
will have been studying过去将来should study
would studyshould be studying
would be studyingshould have studied
would have studiedshould have been studying
would have been studying
考试中出现的一般有以下几种。
I、一般现在时
一、表示一般性或经常发生的动作或状态
1）In general ［A］ ，newspapers emphasize current news，whereas ［B］magazines dealt ［C］more with ［D］ background materials.
2）The adult mosquito usually lives for about ［A］thirty days，although ［B］the life span varied ［C］widely with temperature，humidity，and other ［D］factors of the environment.
3）Industrial buyers ［A］are responsible ［B］for supplying ［C］the goods and services that an organization required ［D］for its operations.
二、表示习惯性动作和状态或普遍的现象或常识
4）It is an accepted ［A］custom in west countries that ［B］men removed ［C］their hats when a woman enters ［D］the room.
5）Certain layers of the atmosphere have special names .
［A］which indicated their character properties
［B］whose characteristic properties were indicating
［C］what characterize their indicated properties
［D］that indicate their characteristic properties
三、表示客观事实、客观规律和客观真理。在宾语从句中，即使主句的谓语动词用了过去时，只要从句表示的是客观真理，从句的谓语动词也要用一般现在时
6）The teacher told them since ［A］light travels faster than ［B］sound，lightning appeared ［C］to go before ［D］thunder.
7）As ［A］a child，I was told that ［B］the planet earth，which has ［C］its own satellite， the moon， moved ［D］round the sun.
四、祈使句必须用动词原形，其否定结构用“don‘t＋动词原形”，如：Go and fetch some water. ／ Don‘t do that.
五、在反义疑问句中，如果主句用肯定句，那么，反问句用否定形式；如果主句用否定形式，那么，反问句就用肯定形式。而且前后在时态上要一致。但祈使疑问句用won‘t you？进行反问。如：See a film tonight， won‘t you？
注：① 祈使句后边可用附加疑问句，以加强语气。如果祈使句用肯定形式，附加疑问句用否定形式；如果祈使句用否定形式，附加句用肯定形式；如： Come here next Sunday， won‘t you？ ／ Don‘t tell it to anyone， will you？ ② 但如果祈使句的前一句有了表示强烈[ZZ（]肯定[ZZ）]的语言环境，即使祈使句用了肯定形式，其附加成分也可以用“will you”（表示肯定，如果是在口语中用降调）。如：Give me the book， will you？joozone.com