I don't know about you, but I talk to my cats, and I'm pretty sure that they understand a lot more than most folks think they do. I know for a fact that they understand "Get off the table" very well indeed, since when I say it, they immediately jump down. I'm also sure that they understand "Stay off the table" and simply choose to ignore it. Cats practice what I call Selective Listening. I think they understand a great deal of what is going on in the house, but are very selective about what they acknowledge.
Willful, that's what cats are. And Stubborn. And Contrary, sometimes. But, of course, their defining characteristic is their legendary Curiosity. They like to know what's going on, even if it's none of their business -- especially if it's none of their business. If Carol is wrapping a present for someone, the cats are right there overseeing the whole process. If I'm slicing vegetables for soup, the cats have to stop by from time to time to see how I'm doing. That must be the reason, since they certainly don't like vegetables, except for Cat Grass.
As an example of Contrary, my cats will drink water out of anything except their own water dish. Carol always keeps a plastic pitcher of water on the kitchen counter to use for watering houseplants. The cats love to drink from that pitcher. One time we bought a little fishbowl and put some of those blown-glass fish in it as a decoration for the cocktail table in the living room. That bowl soon became their favorite place to drink. So much so that ultimately we removed the little glass fish and now just keep it, there on the cocktail table, filled with fresh clean water for their convenience.
The question I most often ask the cats is: "What?" One of them will walk up to me, look up and make a little sound. "What?" I ask. The default answer to nearly every question I ask them is, "Feed me." For Quint, though, sometimes the answer is, "Play with me." For Hedge, the answer is often, "Hey, there's a cat outside the in the yard. Come over and see." Ebony, who is deaf, mostly says, "Feed me NOW," though, of late, I've occasionally had him just walk up to me to say, "Hello."
There is one thing both Carol and I always tell them as we are leaving, whether it is for a shopping trip or for a weekend get-away, and that is: "Guard the house." Laugh, if you will, but it has worked. We've not been burgled since we've had the cats policing the house. I also think it's good for the cats to have something to do when we're away, something useful and helpful. It keeps them busy and productive. The best part is that they don't have to do anything that they aren't already doing. Guarding the house, for cats, mostly consists of checking all the doors and windows regularly, and they already do that. If they're on guard duty, though, it gives their normal activities a bit more purpose which is very good for their self-esteem. However, now that I think about it, I've never really seen a cat with a self-esteem problem. Still, I like to think that giving them a job while we're away is good for them.
When we get home from wherever we've just been, we always acknowledge them for a job well done. I know it always makes me feel better to get praised for doing something well, why should cats be any different? A little, "Well done, guys!!", takes so little effort and, yet, if it makes your cats feel better about themselves it is worth it. If you add, "Are you hungry?" to that greeting, you'll likely receive a reply on the order of: "No problem, always glad to be of service. And yes, a little snack about now would go down just perfectly." So, talk to your cats, and give them a little tasks to do around the house. You'll all be much happier as a result.