Unit9现在完成时精讲+习题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 肯定句 主语+have/has+过去分词 I have finished the task. 否定句 主语+haven't\hasn’t+过去分词 She hasn't finished her work yet. 疑问句 Have /Has +主语+过去分词...? Has Lucy finished the task? 3.标志词 标志词 词义 例句 already 已经 They have already chosen Li Ping to be the team captain. ever 曾经 Have ever chatted online? 你曾经网上聊过天吗? never 从未 I have never chatted online. 我从来没有在网上聊天过。 since 自从 They have worked here since five years ago. for+时间段 ...时间 These books have been kept in the library for a long time. just 刚刚 You have just come back from your hometown. yet 还 Have you handed in your homework yet? 你交作业了吗? recently 最近 David has made great progress recently. once,twice,a few times 几次 I have been there twice since 2015 自2015年以来,我已经去过那里两次 during/in the past+一段时间 在过去的...时间 Our country has made great achievements during the past decades. 我国在过去几十年中取得了巨大成就。 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”:treat →treated ②以不发音的“e”结尾的动词,只在词尾加“d”:create→created ③过去分词 以“辅音字母+y”结尾的动词,将"y"变为"i",再加“-ed”:reply→replied 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:lie→lay→lain 高频易错 1.since和for的区别 ⏺️for+时间段: I have worked here for 12 years. ⏺️since+时间点: I have lived here since 2008. ⏺️since+一段时间+ago=for +时间段: The film has been on since 10 minutes ago. ⏺️since +从句(一般过去时):Two hours have passed since he arrived here. ⏺️It's+一段时间+since(一般过去时句子):It's three years since my grandpa died. 2.have been to/have gone to/have been in ⏺️have been to 去过,已经回来 :I have been to Beijing twice. ⏺️have gone to 去了,还没回来: Sophie is not here. She has gone to Shanghai. 重难点 1.瞬间动词与延续性动词 ✅瞬间动词也称为【终止性动词】和【非延续性动词】。这类动词所表示的动作在瞬间就可以完成,没有延续下去。通常瞬间动词表示的是一次性动作或者动作的相应结果。不能和since/for连用。 ✅延续性动词又称为【持续性动词】,这类动词表示可以持续的动作,或者状态。动作可以延续一段时间,所以这些动词就可以和since与for连用。 如:My grandpa has died since 10 years ago.❎ ➡️ My grandpa has been dead since 10 yea