[误] He has always got a hard mouth and never admit a fault.

　　[正] He never says uncle.

　　注：say (cry) uncle: to give up or in; to surrender; to admit defeat. Mainly used by boys, as when fighting。

　　主要是男孩们打架时的用语，当一方想制服另一方时，就用命令的口气说：“Say uncle!”这时，有的孩子为了表示不服输，就是不说。后来，say uncle 就成了“服输”的代名词，而 not say uncle 就相当于“嘴硬”了。