Want to tell a cat to follow you? Stare him in the eyes, then drag your eyes slowly, turn back and start going. The reverse is true too - that's how a cat tells you to follow you. For a "no" or "get away" I found hissing to be the most effective.

>“Cats don’t understand glass, but they do understand height,” Buffington says

This statement is false, my cat definitely understands what glass is.