Unit 14Section AGrammar FocusThe Present Perfect with already, yet1. Have you watered the plants yet? Yes, I have already watered them.2. Have you finished your homework yet? Yes, I have already finished it.3. Have you found your bike yet? Yes, I have already found it.● 现在完成时的构成 :现在完成时是由“助动词 have / has + 动词的过去分词”构成。助动词要和主语的人称、数保持一致。 现在完成时● 现在完成时的用法 :(1) 表示过去某个时间发生的动作对现在造成的影响或结果。常使用 just, already, yet等时间副词。—Have you had lunch yet? 你吃了午饭吗？ — Yes, I’ve just had it. 是的 , 我刚刚吃过。 ( 现在我不饿了 ) (2) 表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止 , 也可能仍然在进行。常带有 for 和 since 等表示一段时间的状语。He has taught here since 1981.他自 1981 年就在这儿教书。 ( 可能还要继续教 ) I haven’t seen her for four years.我有四年没见到她了。 ● 现在完成时的时间状语 : (1) 用副词 already 和 yet 。 already 一般用于肯定句中 , yet 一般用于否定句和疑问句中。We have already finished our homework. 我们已完成家庭作业了。 They haven’t finished their homework yet. 他们还没有完成家庭作业。 (2) 用 ever 和 never 。多用于否定或疑问句中 , 表示“曾经”或“从未”等。 —Have you ever been to the Great Wall? 你曾经去过长城吗？ — No, I have never been to the Great Wall. 不 , 我从未去过长城。 (3) 用表示到说话为止的过去时间状语 , 如just, before, up to now 等。I have seen her before, but I can not remember where. 我以前见过她 , 但记不起在哪里见过。 (4) 与 since 或 for 表示一段时间的状语连用 , 表示动作或状态从某一时刻开始 , 一直持续到现在。 since 后接时间点或过去时的句子； for 后接时间段。I haven’t seen him for two years. 我已经两年没见到他了。She has taught us since last year. 自从去年起她教我们。I have skated since I was four years old. 从我四岁时...
