have at it
01
开始吧, 请享用
*Start eating your food
例子
John: Here's your hamburger. Have at it.
约翰：这是你的汉堡。开吃吧。
02
来吧, 动手吧
*used in speech to say that someone is welcome to do or take something
例子
If you want to paint, have at it! All the supplies are still out.
如果你想画画，尽管去吧！所有的用品都还在外面。
to have at somebody
01
*to attack someone
例子
I just knew John was going to have at Fred.
to have at something
01
*to attempt or try to do something, particularly with high enthusiasm
例子
Now that finals are over, I need to have at cleaning up my room.
