马马虎虎用英语怎么说？

“马马虎虎”，汉语成语，指做得一般，形容做事不认真，不仔细。可以翻译为“palter with something，be careless/slack，make a hash of something”等。

例句：

他的信我只是马马虎虎地看了一下。
I merely glanced over his letter.

再马马虎虎地开车，就会酿成车祸。
There would be an accident if you drive carelessly like this.