Examples
qù去wài guó外国lǚ xíng旅行bù néng bù不能不dài带hù zhào护照。
去外国旅行不能不带护照。
A passport is something you cannot do without when you go to a foreign country.
我们不能不考虑它。
We have to think about it.
她的父母不能不担心她的伤势。
Her parents can't help worrying about her injuries.