我们想问别人能不能做一件事的时候，常常说“可不可以”。

When we want to ask someone if they can do something, we often say "可不可以".

这是很客气的说法，比“可以吗”听起来更有礼貌。

This is a very polite way of speaking, sounding more courteous than "可以吗".