08 Unit 3 语法与写作(备课件)-【上好课】2021-2022学年高二英语同步备课系列（人教版2019选择性必修第二册）

Unit 3 Food and Culture 语法与写作 1 过去完成时和过去完成时的被动语态 一、过去完成时的概念 过去完成时表示在过去某一时刻或某一动作之前发生的动作或状态, 句中常用 by, before, until, when等词引导时间状语。过去完成时除了强调动作发生在过去 之外, 还常用于间接引语和虚拟语气的句子中。例如: *We had built five new buildings by the end of last year. 到去年年底, 我们已经建了五座新大楼。 *The classroom hadn’t been cleaned before the teacher came. 老师来之前教室还没有打扫过。 *The researchers said at least 4% of the population in those countries had been infected. 研究人员表示, 那些国家至少有4%的人口被感染。 *The letter was passed from one to another until everyone had read it. 这封信从一 个人传到另一个人, 直到每个人都看完。 *Helen said(that)she had moved to another flat. 海伦说她已经搬到另一套公寓去了。 *If only we had listened to their advice! 要是我们听了他们的建议就好了! 过去完成时的标志词和句型 　　by+过去时间点, before, until, hardly/scarcely. . . when. . . ; no sooner. . . than; It was the first/second. . . time that. . . (从句用过去完成时) 二、过去完成时的构成 1. 肯定句: 主语 + had + 过去分词+其他. 2. 否定句: 主语 + had + not + 过去分词+其他. 3. 疑问句: Had + 主语 + 过去分词+其他? 疑问代词/疑问副词 + had + 主语 + 过去分词+其他? *The Union sent letters to the embassy to chee