"used to do something" 是表示曾经做过某事的短语。这个短语来自英语中的动词"use",表示"使用"或"运用",加上"to"和动词原形形成。
例句:
I used to play the piano every day when I was a child. (我小时候每天都弹钢琴。)
He used to work as a teacher before he became a lawyer. (他以前是老师,现在是律师。)
They used to pve in the city, but now they pve in the countryside. (他们曾经住在城里,现在住在乡下。)