例子1 ---小明在家吗？Is Xiaoming at home? ---他刚走，去学校了。He left just now. He went to school [在家=at home；刚走=leave a few minutes ago;学校=school] note: we will never use 他刚才走；but we use 他刚才走的. so 他刚走=他刚才走的=他才走 例子2 --刚才我看见你男友了，和一个小姑娘手拉手的走。just now I saw your boyfriend, with a girl hand in hand --不是吧？他有这么大胆？ Really? 刚才=just now; 看见=see；你男友=your boyfriend; 小姑娘=girl；手拉手=hand in hand 他有这么大胆？=Can he dare? ------------------------------------- usually, if in the beginning of a sentence, we use 刚才，for example 刚才我看见他了、刚才我老师叫我了、刚才我妈妈来了. we also use 【就在刚才，我看到你男友的】 in the middle of a phrase, we usually 刚，for example 我刚看到你男友了（if we use 我刚才看到你男友了, it is OK) ----------------------- Lastly, I want to say, we also usa 刚刚， which has the same meaning as 刚才. Example, 我刚刚到、我刚刚来、他刚刚走

“刚”表示状态تازه “刚才”强调时间。

刚 is short of 刚才

always the same. I think they may like.... 刚才 - just now & 刚 - just （"刚才" more emphasis ”already“, like the past perfect tense） and a significant difference is ”刚才“can be a complete word. ——你上次看见他是什么时候？when did you last see him？ ——就在刚才。Just now. / Just a moment ago. but you can‘t answer ——刚（x）

Actually, they mean the same thing