曾经这样做,但现在不这样做了 --> used to (verb)
I used to eat five meals a day.
我过往一天吃五餐.
习惯,现在还是这样做 --> be/get used to (gerund,即是verb-ing)
I am used to eating five meals a day.
我习惯一天吃五餐.
be gradually doing sth / gradually do sth 是循序渐进地去做某件事.
I gradually overcame the difficulties.
我一步一步的渡过了难关.