1 过去时 eg:He was reading just now.他刚才在读书。
2 现在时 eg:I am busy with finishing my homework just now.我现在正忙着完成作业呢。
just now 有三种含义：
1、at this moment 此时、此刻、眼下
Come and see me later,I'm busy just now!
过些时候再来,我这会儿正忙着呢!
2、during this present period 目前；现阶段
Business is good just mow.
目前生意很红火.
3、onlu a short time ago 刚才；刚刚；一会儿前
I saw her just now.
我刚刚见到过她.
注：just一般不用于否定形式。
温馨提示：答案为网友推荐，仅供参考