关于used的短语结构比较多，总的来说有：
used to do，表示“过去常常做某事”。
He used to cycle to work. 他过去经常骑车上班。
be used to do，表示“某物被用来做某事”。
This knife is used to cut things. 这把小刀被用来切东西。
be/get/become used to doing sth，习惯于做某事。
I am already used to staying up late. 我已经习惯熬夜了。
used to do 表示的意思是 曾经怎样而现在不再做了。
例句 I used to eat meat but I became a vegetarian 5 years ago.
我曾经吃肉但是现在已经吃了5年素食了。
be used to something = get used to something 表示的意思是 习惯了怎样
例句
I can't get used to getting up so early. I'm tired all the time.
我不习惯早起，我总是很累。
He's not used to the weather here yet. He's finding it very cold.
他不习惯（适应）这的天气，他觉得这很冷。