"The cat is drinking water."

Translation: Katten drikker vann.

[jrikhal]

What is the difference between vann and vatn?
When do you use each ones?

[IceColors]

Never use vatn, it's an dialect thing today. It came from norse if you're wondering.
It is just another way to spell/say the same word.

[jrikhal]

Thx for the answer!

[NSElvis]

This got me very confused too, I live in Oslo and vann is the most common word.