Comparing "gang" and "gangcai"
刚 (gāng) and 刚才 (gāngcái) are similar, but they have somewhat different uses.
刚 as "Just happened"
刚 is actually an adverb, and it is placed in front of the verb. It emphasizes that the action just happened a short time ago. It is similar to the English "just." 刚刚 and 刚 are interchangeable in this case.
The key here is that a short time ago is relative, and determined by the speaker. For this reason, 刚 can indicate that something "just" happened 1 second ago, 5 minutes ago, 2 hours ago, 3 weeks ago, or even a year ago. The absolute time is flexible, but from the speaker's perspective, it feels recent.
刚 before An Verb
A few examples:
- 他 刚 到 。This gives the impression that not only did he just get here, but he should still be here.He just arrived.
- 我们 昨天 刚 到 。We just arrived yesterday.
- 真不巧 ，老板 刚 走 。What a bad coincidence. The boss just left.
It would be wrong to use 刚才 instead:
- 他 刚才 到 。
- 我们 昨天 刚才 到 。刚才 should be used for events a lot closer in time than 昨天.
- 真不巧 ，老板 刚才 走 。
And if you mean to say "When I first arrived in Shanghai," use 刚 instead of 刚才:
- 我 刚 到 上海 的 时候 ，谁 都 不 认识 。I didn't know anyone when I just came to Shanghai.
刚 before An Adjective
刚, as an adverb, can also be placed in front of the verb while 刚才 can't be used this way.
A few examples:
- 天 刚 晴 。The sky just cleared up.
- 他 的 感冒 刚刚 好 。He just recovered from his cold.
- 面包 刚 熟 ， 过 一会儿 再 吃 。 The bread just got done cooking. Eat in a little bit.
刚才 as "Just Now"
刚才 is a time noun (like 今天 and 现在), and it expresses that the time that has passed is really short, in near-absolute terms. We're talking no more than 1-30 minutes, in most situations. If it is placed before the verb, it emphasizes what happened in the time that has just passed. It is similar to the English "just now."
A few examples:
- 他 刚才 哭 了 。He was crying a moment ago but he stopped.He was crying just now.
- 我 刚才 看到 他 了 。Sounds like he's not here anymore; I just saw him, but don't see him now.I just now saw him.
- 现在 我 感觉 比 刚才 好 一点 了 。I feel a little better now than just before.
刚才, as a time noun, can directly modify a noun to indicate it is that one from "just now" or "just before," while 刚 can't be used this way.
- 刚 的 事情 太 让 人 生气 了 。What just happened is really upsetting.
- 刚才 的 事情 太 让 人 生气 了 。What just happened is really upsetting.
刚 and 刚才 with 了
You may have noticed that something interesting is going on with regards to 了 in the sentences with 刚 and 刚才. Namely, 了 is not usually required in sentences with 刚, but it is usually required in sentences with 刚才. This is because 刚才 refers to a time in the recent past, and you're usually indicated that something happened just now (started and finished).
Take these sentences for example:
- 我 昨天 看 了 。I looked at it yesterday.
- 我 刚才 看 了 。I looked at it just now.
So these are all simple time "subject + verb" sentences. Notice that when they refer to the past (including the one with 刚才), the action is completed and you need 了. You don't need 了 for things that haven't happened yet (they're just plans, and nothing is completed). And remember that 刚才 always refers to the past.
OK, now what about 刚? Why does it not need 了?
The key is that you don't need a 了 in a sentence with 刚 if the verb indicates a clear result. So, to use the 看 example from above:
- 我 刚 看到 。Adding a 到 to 看 gives the verb a meaning of the result of "looking at."I just saw it.
- 我 刚 看到 了 。了 is not needed here as 看到 includes the result of "looking at."I just saw it.
- 我 刚才 看到 了 。了 is needed here as 刚才 always refers to the past.I saw it just now.
A few more examples:
- 你 刚 知道 吗 ？The verb 知道 always includes the result of "knowing."You just found out?
- 我 刚 听说 。The verb 听说 includes a clear enough indication of result.I just heard.
- 宝宝 刚 醒 。The verb 醒 includes a clear enough indication of result.The baby just woke up.
刚 and 刚才 with 没
OK, so there's also something going on with 没 in sentences with 刚 and 刚才. The deal here is that you can say something didn't happen just now (刚才), but you can't say that something just didn't happen (刚). [Saying that something "just didn't happen" only works in English if you interpret "just" to mean "simply."]
The takeaway? Just don't use 刚 in sentences where you use 没 to negate the past.
- 我 刚 没 看到 。Don't use 刚 with 没 in the past.I just didn't see it.
- 我 刚 没 听懂 。I didn't understand just now.
Use 没 with 刚才 to negate the past.
- 我 刚才 没 看到 。I didn't see it just now.
- 我 刚才 没 听懂 。I didn't understand just now.
- A: 你 刚才 去 哪儿 了 ？Where did you go just now?
- B: 我 去 上厕所 了 。刚 回来 。I went to the bathroom. I just got back.
- A: 那 你 不 知道 刚才 的 事 吧 ？Then you don't know what happened just now?
- B: 刚才 发生 了 什么 事 ？What's just happened?
Sources and further reading
- 现代汉语八百词（增订本） (pp. 216) [ →buy]
- 现代汉语虚词例释 (pp. 190) →buy
- 现代汉语八百词（增订本） (pp. 217) [ →buy]
- 对外汉语教学语法释疑201例 (pp. 28) [ →buy]
- Integrated Chinese: Level 1, Part 2 (3rd ed) (pp. 40- 2) →buy
- 卓越汉语－公司实战篇 (pp. 239) [ →buy]