他对我说过，可是我忘了。

He had told me but I had forgotten.

人虽然老了，可是心却不老。

He is old yet his heart is young.

虽然他为人严峻，可是很公道。

He is very strict but he is very fair.

想给他写信，可是总没有时间。

I want to write a letter to him but I never have any time.

该去，可是我不想去。

I should go but I don't want to.

虽然贵些，可是东西好。

Although it's a little expensive, it's a good product.

可是这有什么关系呢？

but what does this have to do with it?

她家媳妇那个贤惠，可是百里挑。

This daughter-in-law is very virtuous, she's really one in a million.