现在进行时 1. 表示现在 (说话瞬间) 正在进行或发生的动作。 [例句] He is reading a newspaper now. 2. 表示当前一段时间内的活动或现阶段正在进行的动作 (说话时动作不一定正在进行)。 [例句] What are you doing these days? 3. 表示说话人现在对主语的行为表示赞叹或厌恶等, 常与always, constantly, continually等副词连用。 [例句] He is always thinking of others. 4. 表示在最近按计划或安排要进行的动作。常限于go, come, leave, start, arrive等表“移动”、“方向”的词。 [例句] He is coming to see me next week. 过去进行时 1. 表示过去某时正在进行的动作。 [例句] He was sleeping when Mary came to see him. 2. 动词go, come, leave, arrive, start等的过去进行时常表过去将来时。 [例句] She said she was going to Beijing the day after tomorrow. 一般现在时 1. 表示现在习惯或经常反复发生的动作或存在的状态, 常与usually, always, sometimes, often, every day / week / month / year等时间状语连用。 [例句] He often does his homework in his study. 2. 表示主语现在的特征、性格和状态。 [例句] The dictionary belongs to me. 3. 表示客观规律或科学真理、格言, 以及其他不受时间限制的客观存在。 [例句] The moon goes around the sun. 4. 在有连词if, unless, before, as soon as, when, once, however等引导的时间、条件和让步状语从句中, 用一般现在时表将来。 [例句] If you work hard, you won’t fail in the exam. 一般过去时 1. 表示过去某一时间发生的动作或存在的状态。 [例句] She went to the zoo yesterday. 2. 在时间、条件状语从句中代替过去将来时。 [例句] He said when she came he would tell her. 一般将来时 1. 表示将来发生的动作或存在的状态, 常与表示将来的时间状语连用。 [例句] I don’t know what will happen in the future. 2. 常用来表示将来时的结构包括： (1) shall / will + 动词原形：(单纯) 表将来, 一般不用于条件句。 (2) be going to + 动词原形：(计划)打算做……。 (3) be about to + 动词原形：即将或正要去做某事,通常不与时间状语连用,但可与when引导的从句连用。 (4) be to + 动词原形：预定要做……。 (5) be doing 表示按计划、安排即将发生的动作,常与go, start, set out, leave, reach, arrive, return, come, move等表位移的动词连用。 现在完成时 1. 表示过去发生或已经完成的某一动作对现在造成的影响或结果。 [例句] —Have you had your supper yet? —Yes, I have just had it. 2. 常与介词for, during, in, within, over等引导的时间状语连用, 表示过去的某一行为一直延续到现在。 [例句] I haven’t seen my English teacher for a long time. 3. 表示反复或习惯性的动作, 常与several times, once, twice, frequently等频度副词连用。 [例句] I have been to the USA several times. 4. 表示从过去到现在没有发生过的动作。 [例句] I haven’t swept the floor for a week. 5. 用在时间、条件状语从句中, 表示从句动作先于主句动作完成。 [例句] I’ll tell him after you have left. 6. 在“最高级+ 名词”或在“这是第几次…”之后跟定语从句，从句用现在完成时。 [例句] ①This is the third time I have been there. ②This is the best tea I have ever drunk. 过去完成时 1. 表示在过去某一时刻以前已经开始并一直延续到这一时刻、或是在此刻前已经完成的动作。 [例句] By the end of last term, we had learned 1,000 English words. 2. 有些动词 (如： hope, think, expect, mean, intend, suppose, want等) 的过去完成时可表示过去未曾实现的希望、打算或意图。 [例句] I had hoped to see more of Beijing.
