acknowledge所承认的是不对的或不光彩的事实; confess指承认“错误及罪行”;例如:

He acknowledged that he was your inferior.他承认他不及你。

He confessed where he had hidden the money.他供出了他藏钱的地方。

acknowledge强调在一定压力下承认,例如:

Dan acknowledged himself as criminal.达恩承认自己是罪人。

acknowledge所承认的一般是隐蔽的, confess所承认的不一定是隐蔽的。例如:

Jane acknowledged using her father's motor-car.珍妮承认用了她父亲的摩托车。

The police have confessed themselves completely puzzled by this strange crime.警方承认他们完全被这桩奇特的罪案搞糊涂了。