I only stayed for a short while.
我就逗留了一小會。
You were there quite a while (= a long time), weren't you?
你在那裡留了很長時間,是不是?
"When did that happen?" "Oh, it was a while ago (= a long time ago).
「那是甚麼時候發生的?」「噢,是很久之前了。」
I haven't seen him for a while (= for a long time).
我已經很久沒見到他了。
I'll be fine in a while (= soon).
我很快就會好的。