第 47 课 · 第 4 阶段: 时态与情态动词
现在完成时与一般过去时
中级Present perfect vs past simple
构成与用法
I've lost my key（与现在有关）vs I lost it yesterday（已结束的时间）
1.关键区别
这两种时态都讲已经发生的事。区别在于说话人站在哪里看：现在完成时从现在看（这件事现在仍然重要），一般过去时则把动作放在已经结束、翻篇了的时间里。
| 现在完成时 | 一般过去时 | |
|---|---|---|
| 形式 | have/has + V3 | V2 (-ed), did/didn't + V |
| 时间 | 没说出来，或还没结束 | 已经结束 |
| 重点 | 到现在为止的结果或经历 | 什么时候、怎么发生的 |
| 例句 | I've lost my key. | I lost it yesterday. |
快速检验：句子里有没有（或明显暗含）已经结束的时间？有 → 一般过去时。没有，而且现在仍然重要 → 现在完成时。不要靠“了”“过”“已经”这类词来判断——决定时态的是时间框架。
2.时间词
时间词常常决定用哪个时态：
| 一般过去时（已结束的时间） | 现在完成时（到现在为止） |
|---|---|
| yesterday, last night, last summer | today, this week, this year |
| in 2019, on Monday, at 6 o'clock | so far, up to now, recently, lately |
| three days ago, a moment ago | just, already, yet, ever, never |
| When…? What time…? | How long…? (+ for / since) |
Today、this morning、this week 在这段时间还没结束时用现在完成时，结束以后就用一般过去时。
I've drunk two coffees this morning.
今天上午我已经喝了两杯咖啡。（说话时还是上午）
I drank too much coffee this morning, and now I can't sleep.
今天上午我咖啡喝多了，现在睡不着。（上午已经过去了）
Linh has called me four times this week!
阿玲这周已经给我打了四次电话了！
3.现在的结果，还是已结束的事件
同一件事，换个时态，要表达的意思就变了：
I've broken my glasses, so I can't read this.
我把眼镜摔坏了，所以看不了这个。（现在的结果）
I broke my glasses last month, but I've got new ones now.
我上个月把眼镜摔坏了，不过现在已经配了新的。（已结束的事件）
Have you ever been to Thailand? — Yes, I went there in 2022.
你去过泰国吗？——去过，我 2022 年去的。
When did you start learning English?
你是什么时候开始学英语的？（不说：When have you started）
4.讲新闻：先用现在完成时，再换成一般过去时
人们讲新消息时，常先用现在完成时（消息本身），讲细节时再换成一般过去时——因为这时已经有了明确的时间和地点。
I've finally passed my driving test! I took it last Friday.
我终于通过驾照考试了！是上周五考的。
Hoa has had her baby! The little girl was born at 3 a.m.
阿花生了！小女孩是凌晨三点出生的。
There's been an accident on the bridge. A bus hit a motorbike.
桥上出车祸了，一辆公交车撞了一辆摩托车。
美国人，尤其是在口语中，说刚发生的事常用一般过去时：I just got home. / Did you eat yet? 英国人一般用现在完成时：I've just got home. / Have you eaten yet? 两种都对——但有已结束的时间（yesterday、last week、ago）时，英式和美式英语都用一般过去时。
5.仍然如此，还是已经结束
对于持续的情况，现在完成时表示现在仍然如此；一般过去时表示已经结束。已经去世的人或已经过去的人生阶段也是如此。
My dad has been a taxi driver for ten years.
我爸爸开出租车已经十年了。（他现在还在开）
My dad was a taxi driver for ten years. He retired in 2020.
我爸爸开了十年出租车，2020 年退休了。（现在不开了）
My grandfather never learned to drive.
我爷爷一辈子都没学会开车。（他已经不在世了）
6.常见错误
I have visited my aunt in Can Tho last month.I visited my aunt in Can Tho last month.
last month 是已经结束的时间 → 一般过去时。
When have you started learning English?When did you start learning English?
When…? 问句用一般过去时。
I read five books so far this month.I've read five books so far this month.
so far = 到现在为止，这个月还没结束 → 现在完成时。
Minh has finished university in 2021.Minh finished university in 2021.
有明确的年份 → 一般过去时。
I've met your brother at the party on Saturday.I met your brother at the party on Saturday.
说了时间和地点 → 一般过去时。
Have you ever been to Japan? — Yes, I've been there in 2019.Yes, I went there in 2019.
一旦说出年份，就要换成一般过去时。
例句
- I lost my keys yesterday, but Lan found them this morning.
- We went to Phu Quoc in 2019.
- I saw that film last weekend.
- My brother has sent three emails to the bank so far this week.
