I've paid this bill twice by mistake.

我弄错了 把这张账单付了两次

I took your bag instead of mine by mistake.

我不巧错拿了你的包。

He opened Ingrid's letter by mistake.

他误拆了英格丽德的信。

He drilled through the wall by mistake.

他误将墙壁钻穿了。

I did it by mistake.

我误做了这事。

I was aiming at the tree but hit the car by mistake.

我对准树射击，不料误中了汽车。