现在进行时的基本用法： a. 表示现在( 指说话人说话时) 正在发生的事情。 We are waiting for you. b. 习惯进行：表示长期的或重复性的动作，说话时动作未必正在进行。 Mr. Green is writing another novel.(说话时并未在写，只处于写作的状态。...
1) 构成will / be going to do sth. 2) 概念 a. 状态完成：表示某事继续到将来某一时为止一直有的状态。b. 动作完成：表示将来某一时或另一个将来的动作之前，已经完成的动作或一获得的经验。 They will have been married for 20 year...
1) 两个动作如按顺序发生，又不强调先后，或用then，and，but 等连词时，多用一般过去时。 When she saw the mouse，she screamed. My aunt gave me a hat and I lost it.2 ) 两个动作相继发生，可用一般过去时；如第一个动作...
1) 用于完成时的区别延续动词表示经验、经历； 瞬间动词表示行为的结 果，不能与表示段的时间状语连用。 He has completed the work.他已完成了那项工作。 (表结果) I've known him since then. 我从那时起就认识他了。(表经历)2) 用于til...
1) since +过去一个时间点 (如具体的年、月、日期、钟点、1980, last month, half past six)。 I have been here since 1989. 2) since +一段时间+ ago I have been here since five m...
Since 用来说明动作起始时间，for用来说明动作延续时间长度。I have lived here for more than twenty years.I have lived here since I was born..My aunt has worked in a clinic since...
1）It is the first / second time. that结构中的从句部分，用现在完成时。 It is the first time that I have visited the city. It was the third time that the boy had been...
现在完成时用来表示之前已发生或完成的动作或状 态，其结果的确和现在有联系。动作或状态发生在过去 但它的影响现在还存在；也可表示持续到现在的动作或 状态。其构成： have (has) +过去分词。...
意为："意图"、"打算"、"安排"、常用于人。常用词为 come, go, start, arrive, leave, stay等。 I'm leaving tomorrow. Are you staying here till...
1）下列动词：come, go, arrive, leave, start, begin, return的一般现在时表将来。这主要用来表示在时间上已确定或安排好的事情。 The train leaves at six tomorrow morning. When does the bus star?...