You'd better check with the boss. 你最好和老板确认一下。

　　Did you check with security? 你和保安确认过了？

　　I wanted to check with you first. 我想先和你确认一下。

　　Check with me about stuff like this. 这种事情先和我确认一下。

　　She didn't check with her boss before she began.  她在开始的时候没有和老板确认。

　　I'll bet she's in trouble with him.  我打赌她肯定有麻烦了。