I know him, but not very well.

我跟他认识倒认认识，就是不太熟。

《新英汉大辞典》

Yes, I can, but not very well.

我能说一点，但不是很好。

youdao

Sam: Really, I can play golf, too. - but not very well.

萨姆：真的，我也会打高尔夫。——但不是很好。

youdao

Rahman is not well known in the western world but he is very famous in his native India.

VOA: special.2009.02.20

So the Hyksos theory is one that got people very excited for a while, but is really not well supported.

因此希克索斯理论能让人兴奋一阵子，但是并没有得到很好的证实。

耶鲁公开课 - 旧约导论课程节选

All right. It's all very well. You're not an author, but I secretly think I'm an author, right?"

很好，你不是个作家，但是我私下认为我是，可以不？“

耶鲁公开课 - 文学理论导论课程节选

Wunderlist is one of those apps that's beloved by productivity nerds, but not very well known outside of those circles.

ENGADGET: Wunderlist 2 debuts, ditches HTML5 for native apps on Android, Windows, iOS and Mac

So, in a way, the whole erotic risk factor of the Internet is being able to use it but not very well.

NEWYORKER: The Visionary

The story they tell is surely revolting, but not very well reasoned.

FORBES: Book Review: Reckless Endangerment by Gretchen Morgenson and Joshua Rosner