Many of us have to spell words such as "out," "cookie," and "bath" when conversing with other people, lest we unnecessarily excite our pets. And even then they often understand. I've actually had clients who resorted to using a second language around their dogs, but after a while their perceptive pooches caught on. Who says dogs don't understand us?
How to Get Your Dog to Do What You Want (ed. Ballantine Books, 2012) - ISBN: 9780307792310