What is the difference between 可是（kě shì）， 但是 （dàn shì）， and 不过 （bú guò） in Chinese? I know they all mean ‘but‘， so what is the difference?

可是 is a “but” used more like “although”. you could say is a weaker “but”

但是 is the strongest “but” out there, can be used as “but”, though it sounds more like a “however”, and is used for more dramatic effect after pauses in the utterance.

不过 is also somewhat similar “although”, but it’s more used when indicating a small detail that cannot be missed . something like “bear in mind that”. Also used as 只不过…而已 , as in “it’s only that…” when introducing a sentence contrary to what you just said.

But yeah, it’s about getting a feel for the language. 语感， if you will. Remember that 但是 is the strongest. Then it’s up to you concerning how strong you use the word.