Your Great Dane will look to you for guidance, not by verbal commands alone, dogs can read human body language and emotion quite easily. (all-about-great-danes.com)
Just as it does with other animals, human body language also sends a message. (sciencemag.org)
If you can read human body language and facial expression, a little practice is all that is needed to learn the cat's facial language. (petpeoplesplace.com)