Unit 1 Present perfect tense grammar课件 2022-2023学年牛津译林版八年级英语下册

Unit 1 Past and Present Grammar 1. To master the structure and basic usage of present perfect tense(PPT). 2. To learn the rules of forming the past participles of verbs. 3. To learn some time expressions used in PPT. Learning aims 现在完成时(Present Perfect Tense)表示“过去持续到现在的动作或状态,或已完成但对现在有一定影响的动作”。 Basic form: Sb. + have/has (not) + done(过去分词). Have/has + Sb. + done...? When do we use present perfect tense —Yes, sb. have/has. —No, sb. haven’t/ hasn’t. 1. We use the present perfect tense to talk about an action that started in the past and continues to the present. 表示过去开始持续到现在的动作。 Cory went to Beijing two years ago. Cory has lived in Beijing for two years. 2. We use the present perfect tense to talk about an action that happened in the past and has a connection with the present. 表示过去发生的或已完成的动作对现在造成的影响或结果。 Eddie _ Hobo's food just now. Eddie _ Hobo’s food. (Eddie ate the food and now Hobo has nothing to eat. ) Past Present ate has eaten 3. We use the present perfect tense to talk about how many times an acton has happened till now. 表示直到现在一个动作发生(重复)的次数。 Bill visited Australia in 2002 and 2020. Bill has been to Australia twice. It is the first time that I have been here. Past Present already, (not) yet, ever, never, just, before, recently, for, since, over+一段时间, so far... Adverbs of time 时间副词 1.★ already “已经”,用于肯定句中(句中或句末都可)。 yet 用在疑问句或否定句句尾时,表示“还”。 “公交车开走了吗?” “是的,已经开走了。” “不,还没有开走。 ” “Has the bus left yet”? “Yes, it has already left.” “No, it hasn’t left yet. 2. 副词ever 多用于现在完成时的疑问句中,也可用于肯定句,表示“曾经”;never表示否定,表示“从未”。 - Have you ever watched the World Cup? 你曾经看过世界杯吗? -This is the best film I have ever seen. 这是我曾看过的最棒的电影。 - I have never watched the World Cup. 我从未看过世界杯。 3. 用表示到说话时为止的时间状语 如 : just, before, over/in the past few years 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。 Our hometown _ over/in the past few years. 最近几年我们的家乡已变化很多。 has changed a lot for & since : (2) since + (1) for + 一段时间 Tip: 此时主句中的动词必须是长动作(延续性动词)! 过去时间点 一段时间+ago 一般过去时的从句 since