有没有know sth 必须是know about sth吗

有啊。
know英音：[nəu]美音：[no]
—及物动词 vt. [W]
1.知道;了解;懂得[O2][+(that)][+wh-]
I knew she was against us. 我知道她反对我们。
2.认识;熟悉
We have known each other for many years. 我们相互认识多年了。
3.认出;辨别[(+by/from)]
I know right from wrong. 我能辨别是非。
4.体验,经历
I have known hunger and hardships. 我经历过饥饿和困苦。
5.(仅用于过去时和完成时)见到过,听到过[O2][O3]
I have never known him to lie. 我从没有听说过他撒谎。
6.精通(语言等)
He knows five languages. 他精通五种语言。
—不及物动词 vi. [W]
1.知道;了解,懂得[(+about/of)]
There is one or two things I'd like to know about. 有一两件事我很想
知道。

两个都有,因为know既可作vi,又可作vt.

有know sth