HSK 3 · VERSION 2.0#82
Comparing “gāng” and “gāngcái”
刚 vs 刚才
How it works
Both relate to the recent past, but they are not the same.
The difference
刚 = just, often before the verb, can connect to the present 刚才 = just now, a clear time word
Example sentences
我刚到家。
I just got home.
我刚才在楼下看见他。
I saw him downstairs just now.
老师刚走。 / 老师刚才来了。
The teacher just left. / The teacher came just now.
Usage note
刚 is more grammaticalized as an adverb. 刚才 is a clear time expression.