CreatureTeacher's comments are accurate as well as humorous. Dog's "learn" by repetition in conjunction with their natural instincts. That's why we reward them with a treat for good behavior. We all make the mistake of believing our dogs understand the word "sit" etc. They don't, they know the "sound" sit means treat/reward if I do this. (If that makes sense). If you talk to your dog (I think most of do)

he will look at you waiting for a sound that he knows. His ears will perk up at the mention of the word "walk", "treat", "hungry" etc. The other 10 words you said mean nothing.
When you arrive home and there is a mess on the carpet, he looks guilty because he is reading your body language and tone of voice. He knows the alpha is unhappy but cannot associate it with the mess.
Whenever possible, I take Chaz for a walk before I leave for any length of time. Still accidents happen.