On time / in time, at the end / in the end

on time = 按计划的时间，符合时刻表或约定——没有迟到（“准时”）。常用于火车、公交、会议、课程和截止日期。反义是 late。

• The train left on time, at 8:00 exactly.

  火车准时出发了，正好八点。

• Please be on time tomorrow. The meeting starts at nine.

  明天请准时到。会议九点开始。

• Hai is never on time. He's always ten minutes late.

  阿海从来不准时。他总是迟到十分钟。

in time = 来得及做某事，或在某事发生之前赶到（“及时”）。两个常见结构：in time for + 名词 和 in time to + 动词原形。反义是 too late。

• We got to the cinema in time for the start of the film.

  我们及时赶到了电影院，赶上了电影开场。

• Will the package arrive in time for Tet?

  包裹能在春节前寄到吗？

• I didn't get to the station in time to catch the last train.

  我没能及时赶到车站，没赶上末班火车。（= 我错过了火车）

💡快速判断：问“和计划相比晚了吗？”→ on time。问“来得及做某事吗？”→ in time。

• just in time = 刚好来得及；再晚一会儿就来不及了。
• in good time（主要是英式）= 提早，时间很充裕。
• 单独用的 in time 还可以表示最终、过一段时间以后——和时间表无关。
• 这两个短语都不加冠词：表示这些意思时，不说 “on the time” 或 “in the time”。

• The ambulance arrived just in time.

  救护车及时赶到了。

• We left early and got to the airport in good time.

  我们出发得早，提前到了机场。

• It hurts now, but in time you'll forget about it.

  现在是很痛，但时间长了你就会忘掉的。

at the end (of something) = 在一段时间、一件事或一个地方的最后部分（“在…的末尾、尽头”）。通常带 of：at the end of the month / the film / the class / the street。意思明确时，可以省略 of … 部分。

• We pay the rent at the end of the month.

  我们在月底交房租。

• Everyone cried at the end of the film.

  电影结尾时大家都哭了。

• Our house is at the end of the street.

  我们家在这条街的尽头。（地点：也用 at the end of）

• I'll answer your questions at the end.

  我最后再回答大家的问题。

in the end = 最终、到头来——经过很长的过程，经历很多变化、犹豫或问题之后的结果。它通常放在句首或句末，后面不跟 of。

• We couldn't decide where to go, so in the end we stayed at home.

  我们定不下来去哪儿，结果最后待在了家里。

• The exam was really hard, but in the end I passed.

  考试真的很难，但我最后还是通过了。

• He said he wasn't coming, but he came in the end.

  他说他不来，可最后还是来了。

💡如果后面跟 of，几乎肯定用 at：at the end of the film，不说 “in the end of the film”。In the end 单独使用，意思是“最终”。

In the beginning 强调“起初是这样，后来变了”，和 at first 一样。At the beginning of + 具体的时间或事物，只是表示它的开头部分。

• In the beginning, living alone was hard, but now I love it.

  起初一个人住很难，但现在我很喜欢。

• The rainy season starts at the beginning of May.

  雨季从五月初开始。

• At last! The bus is here.

  终于来了！公交车到了。

• ✗The concert started in time, at exactly 7 p.m.

  ✓The concert started on time, at exactly 7 p.m.

  按计划的时间 → on time。

• ✗I didn't get there on time to see the start of the match.

  ✓I didn't get there in time to see the start of the match.

  来得及做某事 → in time to + 动词。

• ✗We looked everywhere, and at the end we found the cat.

  ✓We looked everywhere, and in the end we found the cat.

  经过很长过程后的结果 → in the end。

• ✗In the end of the film, the hero dies.

  ✓At the end of the film, the hero dies.

  某事的最后部分 → at the end of。

• ✗Please be on the time.

  ✓Please be on time.

  不加冠词。