I know him, but we dont frequently see each other.

我认识他，但我俩并不常来常往。

《新英汉大辞典》

A I dont know which I like best. They are all so different.

A我不知道我最喜欢哪个建筑，它们各具特色。

youdao

Robbie Turner: Yes but, if all we have, rests on a few moments in a library three and a half years ago then I am not sure, I dont know...

罗比：对，可是，如果我们所有的一切只剩下三年半前书房的那一刻，那么我不能肯定，我不知道……

youdao

"It is so nice, we are watching soccer, I dont even know his name but I can just say, Yo,what is the score my man?

VOA: standard.2010.06.19

"I dont know if we will appeal - I will see what we can do about that, " said his club manager Arsene Wenger.

BBC: Fabregas and Brown charged by FA

"I dont know what the percentage it affected us was, " 49ers coach Jim Harbaugh said.

WSJ: Super Bowl XLVII: Baltimore Ravens Have Just Enough Power to Beat San Francisco 49ers