第 109 课 · 第 9 阶段: 连接观点
By 与 until
中级By vs until
构成与用法
by + 时间（最迟在……之前），until + 时间（一直到……），by the time…
1.基本区别
两个词都和时间点搭配，但看待这个时间点的角度不同。
| 意思 | 搭配 | 例句 | |
|---|---|---|---|
| by + time | 不晚于（截止时间） | 只需要在那之前完成的动作 | Please reply by Friday. |
| until / till + time | 一直到（持续，然后停止） | 持续的状态或动作 | I'll wait until six. |
问问自己：这个动作是一直持续到那个时间，还是只需要在那之前完成？持续 → until。截止时间 → by。
2.By——截止时间
1. by + 时间 = 在那个时间或之前
I need the report by Friday.
我需要在星期五之前拿到报告。
Dinner will be ready by seven.
七点前晚饭就做好了。
The parcel should arrive by the end of the week.
包裹应该在这周末之前送到。
2. by then / by that time / by now
Call me at nine. I'll be home by then.
九点给我打电话吧。到那时我已经到家了。
They left at noon, so they should be in Da Lat by now.
他们中午出发的，所以现在应该已经到大叻了。
3. 常和完成时连用（见“将来完成时”一课）
By next summer, I'll have saved enough for a motorbike.
到明年夏天，我就攒够买摩托车的钱了。
By 2020, she'd moved to Saigon.
到 2020 年，她已经搬到西贡了。
3.Until——一直到
1. 某种状态一直持续到某个时间，然后停止。 Till = until，口语中很常见。
The shop is open until 10 pm.
这家店营业到晚上 10 点。
Let's wait here until the rain stops.
我们在这儿等到雨停吧。
I work from nine till five.
我从九点工作到五点。
2. not … until = 直到……才（比预期晚）
I didn't get home until midnight.
我直到半夜才到家。
The film doesn't start until eight.
电影八点才开始。
3. until + 从句：用现在时表示将来（不用 will）
Stay here until I come back.
在这儿待着，等我回来。（不说：until I will come back）
I'm not leaving until I've finished this chapter.
不读完这一章我就不走。
4.By the time + 从句
By the time + 从句 = “等到这件事发生时，另一件事已经发生了”。主句常用完成时，因为那个动作发生在这个时间之前。
| 时间 | 句型 | 例句 |
|---|---|---|
| 过去 | By the time + 一般过去时，… had + V3 | By the time we got to the cinema, the film had started. |
| 将来 | By the time + 一般现在时，… will have + V3 | By the time you get here, I'll have finished. |
By the time I found my keys, the bus had already left.
等我找到钥匙时，公交车已经开走了。
By the time you read this, I'll be on the plane.
等你读到这封信时，我已经在飞机上了。（不说：By the time you will read）
表示这个意思时不要说 “until the time”。要表达“等到……时，某事已经发生了”，一律用 by the time。
5.By 和 until 对比
You can stay until Sunday.
你可以一直待到星期天。（一直待到星期天）
You have to leave by Sunday.
你必须在星期天之前离开。（星期天或之前离开）
I'll be at work until six, so I'll be home by half past six.
我要工作到六点，所以六点半之前到家。
I can't finish it by Friday.
我星期五之前完成不了。（会错过截止时间）
I won't finish it until Friday.
我要到星期五才能完成。（星期五完成，不会更早）
6.常见错误
I have to finish this essay until Monday.I have to finish this essay by Monday.
完成某事的截止时间 → 用 by。
We stayed at the party by midnight.We stayed at the party until midnight.
待着是持续到那个时间 → 用 until。
Until the time I got to the station, the train had left.By the time I got to the station, the train had left.
固定说法：by the time。
By the time you will arrive, we'll have eaten.By the time you arrive, we'll have eaten.
by the time 后面用现在时表示将来。
By the time we arrived, the shop closed.By the time we arrived, the shop had closed.
更早发生的动作 → 用过去完成时。
例句
- Please send me the report by Friday. I need it for the meeting.
- The shop is open every day until ten o'clock at night.
- You can borrow my bike until Sunday.
- I'll wait for you until six o'clock, but then I have to leave.
