Have they ever travelled by train? No, never.
(5) just
用于句中, 表示“刚刚” I’ve just had breakfast. What have they just done?
(6) before 用于句末, 表示“以前” I’ve seen it before. Has she ridden a bike before ?
② before与ago，just与just now
before表示在过去某时间的“以前” ，常单独用于现在完成时中，一般不与 表示一段时间的词语连用，而ago表示现 在看来的“以前” ，常用“一段时间 +ago”的形式，与过去时连用；just常与 现在完成时连用，多用于句中助动词之 后修饰谓语动词，just now多与一般过去 时连用，一般用于句末。如：
含义及用法：
2. 表示一个从过去开始，一直持 续到现在的动作或状态。 通常和for或since引导的时间状语 连用。 注1):要使用延续性动词
（1）for + 一段时间 I have been here for 5 weeks. He’s studied English for 3 years. She has worked for 10 hours.
注 2) ：对 for 或 since 引导的时间 状语提问用how long I have lived here for 10 years. How long have you lived here?
（2）since + (过去的)时间点或一般过去 时态的句子
I have been here since 2000. He has worked as a teacher since 5 years ago? They’ve lived in Beijing since they married in 2000.
二 含义及用法：
1 表示过去发生的动作或做过的 事情对现在的影响和产生的结果
常用的关键词
yet(否/疑), already 已经 ever/never 曾经/从来不 just 刚刚 before 以前 recently, lately 最近 in the past/last +时间段 过去的… by now, so far, up to now, till now 迄今 once, twice… 一次… all/in one’s life 某人一生
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Mother has just cleaned the house. Mother hasn’t cleaned the house yet.
(3) ever 肯定句/疑问句 : 句中 “曾经”
I’ve ever been to Beijing. Have you ever been to Beijing?
现在完成时
The Present Perfect Tense
一 构成:
have/has+动词过去分词 (pp)
肯定 主语+have/has + pp 否定 主语+have/has not + pp 疑问 Have/Has + 主语+ pp+其他 答语：Yes, 主+have/has. No, 主 +haven’t/hasn’t.
（1）already
肯定句: “己经”
I’ve already had breakfast. (更常见) = I’ve had breakfast already.
Have you had breakfast already？ (表示强调)
一般疑问句: 句末(表示惊讶的语气) “难道”
(2) yet
否定句:句末 “还(没)” I haven’t had breakfast yet.
疑问句: 句末 “己经” Have you had breakfast yet?
注意：当在肯定句中含already或 just，变否定时，在句末加yet。
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I have already seen the film. I haven’t seen the film yet.
I have finished my homework. I have not finished my homework. Have you finished your homework? Yes, I have./No, I haven’t. She has been to Europe. She hasn’t been to Europe. Has she been to Europe? Yes, she has./No, she hasn’t.
(4) never 否定句: 句中 “从来没有” I’ve never been to Beijing.
注: 带ever的肯定句变否定句时, 将 ever变never
He has ever made meal. He has never made meal.
带ever的一般疑问句作否定回答时 可用“No, never.”
• Have you met him before? • 你以ቤተ መጻሕፍቲ ባይዱ见过他吗？ • My brother met her in the street two days ago. • 我哥哥两天前在街上遇到了她。 • I have just had breakfast. • 我刚吃过早餐。 • She had breakfast just now. • 她刚吃了早餐。
动词过去分词 (pp)变化规则
1. 规则动词：与过去时变化相同。 (1) 一般+-ed work---worked---worked (2) 以“ e ”结尾, + - d 。 live---lived ---lived (3) “辅音字母 + y” 结尾，y 变 i, + -ed。 cry---cried---cried (4) 重读闭音节结尾(辅元辅)，双写辅音 字母后+-ed 。 drop---dropped--dropped 2 、不规则动词，见不规则表（p104）