今天我在学两个常用语： back to square one和hankering.
Back to square one意思是回到起点。
Square one is not an actual place. It means going back to the beginning. usually people say, "back to square one." This means that they did a lot of work, but it did not help them get any closer to their goal.
square one就是从头开始的意思。比如，我写论文忘了存盘，结果电脑死机全丢了，只好从头再来，这种情况就可以说I was back at square one.
To have a hankering, for something means that you want that thing. Usually someone would say they have a hankering for a type of food or drink.