How cats communicate
They don't. They issue orders, and take vengeance upon those who disobey. Vengeance may be limited to severe turning of the back. When a cat turns his back on you, you know it, it actually hurts. That might be the cat's most awesome weapon; ignoring the heck out of you. They also scratch.
This article has been written three times already, and it keeps disappearing. It matters little, it was mainly about how cats know sixty ways of ignoring you, let it be for now...