時態
1、常用時態的形式：(以動詞“study”為例)
時間：現在 過去 將來 過去將來
狀態
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一般 study studied shall/will study should /would study
studies
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進行 am/is/are was/were shall/will be should/would be
studying studying studying studying
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完成 has/have had shall/will should/would
studied studied have studied have studied
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完成 has/have had been shall/will should/would
進行 been studying studying have been studying have been studying
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2、理解上表的要點：
1)、過去將來：表示過去某時看來將要發生的動作或情況。
2)、完成時與完成進行時的區別：完成進行時比完成時更強調動作的延續性。
E：He has been watching TV for three hours (強調他還要看下去)
He has been watched TV for three hours(不一定要看下去了)
3、某些時態的不同表示方式：
1)、表示將來發生的動作或情況的幾種形式：
a. shll/will +動詞原形
b. be going to do sth 常用來表示最近打算要做的事情或即將發生的事
c. be to do sth 表示按計劃安排要做的事或要發生的事
d. be about to do sth 表示正要或即將要做的事
2)、現在完成時
a. 表示動作在過去某時發生并已經完成，且對現在有影響。常和以下時間狀語連用：already / yet / before / recently / lately / often / rarely /once 等
E：The issue of "mercy killing"has recently boiled over into a fiere public debate in Europe
b. 表示動作始于過去，持續到現在，可能不將持續下去。常和表示一段時間的狀語連用：for some time , for three years, since, so far , in the past few years, all this while.
E：During the past few years,the public has focued on AIDS.
c. 可以用在時間狀語或條件狀語叢句中，表示將來業已完成的動作。
E：We’ll start at five o’clock if it has stopped snowing by then.
3)、注意點：現在完成時常用于下列句型：
a. It’s/it will be the first /second ……time/day that……
b.This /That is the +形容詞最高級
E1：It’s the first time I have been to ShangHai
E2：This is the second letter I’ve written to you this year
E3：It’s one of the most interesting books I have ever read
現在完成時不能與表示確定的過去時間連用：yesterday,in 2001,a few year ago等，這些狀語一般只用在一般過去時。
