My cat says thanks for her food by nudging my hand when I put it down in front of her. I know it's thanks and not an accidental by-product of trying to get at the food because she won't eat until and unless she has thonked her little snoot into my knuckles. She'll follow me out of the room to do it.
Squoof goes and sits in the bathroom when she thinks it’s time for me to get ready for bed. If I don’t follow her quickly enough she comes back out to glare at me and goes back in.
One night I was watching a movie and was very late going to bed and I found her asleep on the bathmat.