摘要：I'm pretty mad about it, I can tell you. （我可以告诉你，我对此非常生气。） [柯林斯高级学者辞典]

mad有多条义项，其中之一是very angry。

此义项多被词典标上informal，可能因为very angry都不适合正式的沟通场景。

be mad about something指“就某事非常愤怒”，如

【例句1】They're pretty mad about being lied to. (他们对被欺骗很生气。)[牛津高级学者辞典]

【例句2】There's no need to get mad about it! （没必要为此生气！）[朗文当代英语词典]

【例句3】I'm pretty mad about it, I can tell you. （我可以告诉你，我对此非常生气。） [柯林斯高级学者辞典]

be mad at someone指“对某人非常愤怒”，如

【例句4】Are you still mad at me? (你还在生我的气吗？)[剑桥高级学者辞典]

【例句5】We get mad at each other sometimes, like any family. （我们有时会生对方的气，像任何家庭一样。） [朗文当代英语词典]

【例句6】She's mad at me for being late. (她因为我迟到而生我的气。)[牛津高级学者辞典]

【例句7】You're just mad at me because I don't want to go. （你只是因为我不想去而生我的气。）[柯林斯高级学者辞典]

之所以用介词at, 可能是为了表达“力度朝向”，有点类似shout at someone的at。

英式英语也用with someone，如

【例句8】Kerry got really mad with Richard for not doing the washing up. (克里对理查德不洗餐具非常生气。)[剑桥高级学者辞典]

【例句9】His wife will be really mad with him. (他的妻子一定会生他的气的。) [朗文当代英语词典]

with在古英语中的含义为against, opposite。be mad with的with可能是用against的对抗之义。

来源：文泰教育