Comparing "gang" and "gangcai"

刚 (gāng) and 刚才 (gāngcái) are similar, but they have somewhat different uses.

Both are used before the verb but have different meanings

刚 emphasizes action happened not long ago

"刚" is actually an adverb, and it is places in front of the verb. It emphasizes that the action just happened a very short time ago.It is similar to the English "just".

Structure

刚 + Verb

Examples

• 我 刚 说过，不 想 再 说 一 遍。I just spoke, I don't want to speak again.
• 我 刚 看到 他。I just saw him.
• 他 刚 来。He just came.

刚才 emphasize what people did just now

刚才 is a time noun, and it expresses the time that passed is really short. If it is placed in before the verb, it emphasizes what happens in the time that just past. It is similar to the English "just now".

Structure

刚才 + Verb

Examples

• 我 刚才 看 过 了，不 想 再 看 一 遍。I just saw now saw it, I don't want to see it again.
• 我 刚才 看到 他 了。I just now saw him.
• 他 刚才 来 了。I just now came.

刚才 can be used as an attribute while 刚 cannot

刚才 can also mean "time that just past". It can be used as a now to indicate "time before" or "just before"

Structure

刚才 + 的 + Noun

Examples

• 刚才 的 事情 太 让 人 生气 了。
What just happened made people very angry.
• 我 觉得 现在 比 刚才 亮。
I think it's brighter now that just before.
• 刚 的 事情 太 让 人 生气 了。
Just think makes people angry

刚 can be used as "Just" while 刚才 cannot

刚 is an adverb, and it can also spruce up an adjective. It has the same meaning as 刚刚. 刚才 cannot to this.

Structure

刚才 + Adjective

Examples

• 天 刚 晴。The sky just became clear.
• 一 个 面包 刚 够 吃，多 一 个 更 好。One bread is just enough, more is even better.

Examples of right and wrong sentences

• 我 刚才 回家。
• 我 刚 回家。
I just returned home.
• 我 刚才 没 想好 吃 什么，现在 我 想好 了。
• 我 刚 没 想好 吃 什么，现在 我 想好 了。
Just a while ago, I didn't think up what to eat, now I just thought it up.

Example dialog

• A: 你 刚才 去 哪儿 了？Where did you just now go?
• B: 我 刚 上 完 厕所。I jut went to the bathroom.
• A: 那 你 不知道 刚才 的事情 吧？Do you know what just now happened?
• B: 是 不 是 有人 吵架 了？Did some people start arguing?

Sources and further reading

Books

• 现代汉语八百词（增订本） (刚 p.216) →buy
• 现代汉语八百词（增订本） (刚才 p.217) →buy
• 对外汉语教学语法释疑201例 (p.28) →buy

Dictionaries

• 现代汉语词典（第5版） (p.446) →buy