Possible Duplicate:
“Angry with” vs. “angry at” vs. “angry on”
Can the preposition at in the following sentence be replaced by with?
I'm mad at you.
In my mother tongue we say that we are mad with someone, not at.
Learn English – “To be mad at somebody” vs. “to be mad with somebody”
at-withgrammaticalityprepositionsword-choice
Best Answer
In English you are "mad at" a person, institution, etc. You wouldn't say you are "mad with" them.
Inconsistently, you are "angry with" a person, not "angry at" them.