时态

3.1 时态的种类

3.2 一般现在时

3.2.1 一般现在时表示经常性的动作或状态

一般现在时在表示经常性动作或状态时常与often，always，usually，sometimes,everyday,generally等状语连用

• He lives in New York
• We visit him every summer

3.2.2 一般现在时表示客观规律或普遍真理

• Two plus two equals four
• Knowledge is power

即使在主句的谓语动词为过去时态的情况下，宾语从句的谓语动词仍然用一般现在时来表示客观规律或普遍真理

• The teacher told them since light travels faster than sound,lightning appears to go before thunder

3.2.3 一般现在时表示主语的特征或状态

• Air contains oxygen and nitrogen
• Japan lies to the east of China

3.2.4 一般现在时在时间和条件状语从句中表示将来的动作或状态

• I'll let you know as soon as he comes
• We will go fishing if it is fine tomorrow

3.3 一般过去时

3.3.1 一般过去时表示过去的动作或状态

1. 一般过去时通常与表示过去的时间状语连用
   • The train arrived ten minutes ago
   • I was away yesterday afternoon

另外，一般过去时还可以和for或since引导的时间状语连用
* I lived here for five years
* Nothing happened since then

2. 有时一般过去时的时间状语或是在上下文，或是暗含于句中
   • Did you sleep well
   • I saw him on my way to walk

3.3.2 一般过去时在时间和条件状语从句中表示过去将来的动作或状态

• Tom promised to write to us when he reached London
• He said he would let us know if he got any news

3.4 一般将来时

• We shall be pleased to accept your invitation
• My son will be five years old next month

3.5 现在进行时

3.5.1 现在进行时表示说话时或现阶段正在进行的动作

• The telephone is ringing
• We are preparing for the meeting to be held next month

3.5.2 现在进行时表示经常性的动作

现在进行时在表示经常性、重复性或习惯性的动作时必须与always，constantly，continually，repeatedly等频度副词连用

• The child is continually losing keys
• Why are you always complaining

3.6 过去进行时

3.6.1 过去进行时表示过去某时正在进行的动作

1. 过去进行时通常和时间状语连用
   • He was singing just now
   • What were you doing last night
2. 过去进行时可用作其他动作发生的背景
   • I was reading while she was writing
   • Tome walked in when I was having my lunch

有时过去进行时用于主句，位于其后的when引导的从句中表示意外发生的情况

• I was having my lunch when Tom walked in

3.6.2 过去进行时表示过去将来的动作

过去进行时的这种用法多表示过去的打算，通常仅限于come,go,leave,depart,start等一些表示移动的动词

• He said he was leaving the next day
• We were departing two days later

3.7 将来进行时

1. 将来进行时表示预计即将出现或势必出现的情况

   • The train will be arriving soon
   • How long will you be staying for?

2. 将来进行时表示将来一段时间内正在进行的动作

   • We shall be traveling this time next year
   • They will be doing the experiment for seven to nine this evening

3.8 过去将来时

1. 过去将来时表示过去某时之后将出现的情况，通常用于宾语从句中
   • I thought he would come
   • She never imagined that she would become a doctor

3.9 现在完成时

3.9.1 现在完成时表示从过去持续到现在的动作或状态

1. 现在完成时的这种用法通常与由since或for引导的时间状语连用
   • I have waited here since three o'clock
   • I have waited here for three hours

3.9.2 现在完成时表示过去发生的对现在有影响的动作

1. 现在完成时的这种用法有时不带时间状语，有时可以和already，before，ever,just,lately,never,once,recently,yet等一些所指时间不具体的时间状语连用

   • I have lost my keys
   • Have you ever been to Australia

2. 有时现在完成时和now,today,this morning,this week,this year等表示现在的时间状语连用

   • I haven't seen him today
   • They have produced five films this year

3.10 过去完成时

3.10.1 过去完成时表示过去某时之前结束的动作或状态

• When we reached the station,the train had already left
• He told me that he had finished his paper

had + just/barely/hardly/scarcely + done ...when...是表示“刚...就...”或“不等...就...”的固定句型

• I had hardly opened the door when the phone rang
• He had scarcely arrived when he had to leave again

3.10.2 过去完成时表示持续到过去某时之前的动作或状态

• He had worked here for 20 years old by the end of last month
• My sister said she had read three novels since she entered the university

3.10.3 过去完成时表示未实现的愿望

过去完成时表示未实现的愿望的用法仅限于expect,hope,intend,mean,plan,think,want等动词

• I had intended to come,but I was too busy
• I had expected to meet him at the meeting

3.11 将来完成时

3.11.1 将来完成时表示到将来某时已结束的动作或状态

• When you come tomorrow, we shall have found the answer
• He will have forgotten about it before long

3.11.2 将来完成时表示持续到将来某时的动作或状态

• By the time I graduate,I shall have studied English for six years
• He will have been a teacher for a whole year by next Monday

3.12 现在完成进行时

3.12.1 现在完成进行时表示从过去一直持续到现在的动作

1. 现在完成进行时所表示的动作刚刚终止

   • I have been waiting here for you since three o'clock

2. 现在完成时进行时所表示的动作可能继续下去

   • She has been wearing glasses since last year
   • We have been discussing for two hours

3.12.2 现在完成时表示从过去到现在的重复性动作

1. 现在完成进行时的这种用法所表示的并不是一直在进行的动作，而是断断续续地反复发生的动作
   • He has been appearing on TV
   • You have been coming to see me for many years
   • I've been wanting to write you for a long time

3.13 过去完成进行时

过去完成进行时主要持续到过去某时之前的动作

1. 过去完成进行时所表示的动作到某时已经终止

   • The phone had been ringing for two minutes before it was answered

2. 过去完成进行时所表示的动作到某时可能继续下去

   • By last Friday ,he had been working in our company for three years
   • He said he had been practicing on the piano since he was five

3.14 不能用于进行时态的动词

有些动词不能用于进行时态，它们是一些静态动词，这类动词包括表示“存在”和“拥有”的动词、表示感官的动词、表示思维活动的动词，表示情感的动词等，如：be,exist;have,own,possess;see,hear,taste,smell,feel;agree,belive,desire,dislike,doubt等。