“我没空”怎么说

I am in work。这个比较俗，美国人一般说I am standing on others，一般给中国人看是看不懂的。这是我的外教教的

I have no time
I'm not free

If you want to be polite:
This is actually not a good time for me.

I have no time.

I have no time
I'm not free
I don not have any time.
I am busy.

I'm not free.直译。简单明了。