Comparing "yihou" and "zhihou"
Both "以后" (yǐhòu) or "之后" (zhīhòu) mean "after," but there are a few tiny differences in usage.
Similarities between 以后 and 之后
Both can indicate another event happened after a specific time.
Subj. + Specified Time + 以后／之后 + Verb
In situations something happens after something else, you can use 以后. The stipulation with this is that "after WHAT" needs to be explicitly stated. That is, there has to be a "specified time" for 以后 to modify. Otherwise 以后 won't work in those sentences.
以后 and 之后 may be freely interchanged in any of the below sentences.
- 下 过 雨 以后 空气 会 好 很 多 。After it rains, the air will be a lot better.
- 结婚 之后 他们 有 了 两 个 宝宝 。 After getting married, they had two babies.
- 等 我 涨 工资 以后 请 你 吃饭 。 After I get a raise, I will treat take you out to eat.
- 听到 这 个 消息 之后 ，我 高兴 得 一 晚上 没 睡 。 After I heard this news, I was so happy I couldn't sleep the whole night.
Differences between 以后 and 之后
The key to understanding 以后 here is that if it doesn't come immediately after something else, then it's being used by itself. And when 以后 is used by itself, it doesn't mean "after;" it means "in the future."
以后 by Itself Means "In the Future"
- 以后 再 也 不 来 这里 吃饭 了 ， 又 贵 又 难吃 。 In the future I will never come to this place to eat again. It's expensive and the food is terrible.
- 以后 我 可能 会 去 国外 上 大学 。 In the future I might go to college abroad.
- 以后 的 事情 以后 再 说 吧 。 We'll talk about future issues in the future.
之后 by Itself Means "After that"
Compared to 以后, 之后 is a little more flexible. Not only can it be used just like 以后, modifying the time, but it can also appear independently, meaning something along the lines of "after that." While 以后 must come after a specific time to mean "after," it cannot can stand by itself like this.
(Event 1 ，) 之后 + Event 2
- 我 要 先 回家 把 东西 放 下 ，之后 去 咖啡店 找 你 。 I'm going to go home and drop my stuff off first, after that go to the cafe to look for you.
- 去年 夏天 他 来 过 我 家 ，之后 再 也 没 见 过 他 。 Last summer, he came to my house. After that, I haven't seen him.
Common Mistakes with 以后 and 之后
In the following sentences, 以后 is not grammatical when it's not directly coupled with a time or event telling you after what. 之后 can be used here to mean "after that."
- 我 六 点 下班 。 以后，我 去 跟 朋友 吃饭。
- 我 六 点 下班 。 之后，我 去 跟 朋友 吃饭。I will get off work at six o'clock. After that, I will meet a friend for dinner.
- 昨天 我 跟 朋友 吃 完 饭 以后 去 打 篮球 了 。
- 昨天 我 跟 朋友 吃 完 饭 之后 去 打 篮球 了 。When a time is specified, both are fine.Yesterday after finishing eating with my friends, we played basketball.
- 昨天 我 跟 朋友 去 吃饭 了 。 以后，我们 去 了 宠物店 。
- 昨天 我 跟 朋友 去 吃饭 了 。 之后，我们 去 了 宠物店 。Yesterday I ate dinner with a friend. Afterward, we went to a pet shop.