现在完成时 讲义2022-2023学年人教版英语八年级下册

现在完成时 1.意义 ✅表示过去发生的动作，对现在造成的影响或结果。 ✅表示在过去已经开始，并持续到现在的动作或状态。 如： ⏺️ I've already had my lunch。【表示我已经吃过午餐，并且现在不饿】 ⏺️ I've lived here for 10 years. = I've lived here since 10 years ago. 【表示我10年前就住在这里，并且现在也住这里】 2.基本构成 ✅have/has +过去分词 have:第一人称，第二人称及第三人称复数 has:第三人称单数 ⏺️肯定句：主语+have/has+过去分词 ⏺️否定句：主语+haven't（have not）+过去分词 主语+hasn't（has not）过去分词 ⏺️疑问句：Have /Has +主语+过去分词...? 如： I have finished my homework. ➡️ I haven't finished my homework. ➡️ Have you finished your homework? 3.标志词 标志词比较多，如already,ever,never,since,for,just,yet,recently,once，over，in the past+一段时间等等。总结如下： 标志词 词义 用法 位置 already 已经 肯定句 句中或句末 ever 曾经 肯定句，疑问句 句中 never 从未 陈述句与not连用 句中 since 自从 肯定，疑问，否定 句中 for 后＋一段时间 肯定，疑问，否定 句中 just 刚刚 肯定 句中 yet 还 疑问，否定 句末 recently 最近 肯定，疑问，否定 句末 Once,twice ,a few times 几次 肯定，疑问 句末 during/over/in the past/last＋一段时间 在过去的一段时间 肯定，疑问，否定 句末 It's the first time I... 这是我第一次 肯定 句前 如： ⏺️ She has already lived here for 5 years. ⏺️ Have you ever been to Paris? ⏺️ I have never read the book The Journey To The West. ⏺️ My father has worked here since 2008. ⏺️ I've just heard the bad news. ⏺️ It's too early. The supermarket hasn't been opened yet. ⏺️ I have to keep a diary because I have gained weight recently. ⏺️ I have been to Shanghai twice. ⏺️ I've learnt a lot new math knowledge during my stay at my aunt's. ⏺️ A lot of changes have taken place in China in the past 40 years. 4. 过去分词变化【必须记忆内容】 ✅规则变化： ①一般动词，在词尾直接加“-ed” played ②以不发音的“e”结尾的动词，只在词尾加“d” lived ③过去分词 以“辅音字母+y”结尾的动词，将"y"变为"i"，再加“-ed”。 studied ④重读闭音节结尾，末尾只有一个辅音字母，先双写该辅音字母，再加“-ed”stopped ⑤不规则变化 get got gotten 高频易错 1.since和for的区别 ⏺️for+时间段 ⏺️since+时间点 ⏺️since+一段时间+ago=for +时间段 ⏺️since +从句（一般过去时） ⏺️It's+一段时间+since（一般过去时句子） 如： I have worked here for 12 years. I have lived here since 2008. The film has been on since 10 minutes ago. Two hours have passed since he arrived here. It's three years since my grandpa died. 2.have been to/have gone to/have been in ⏺️have been to 去