Researchers in Hungry confirm your dog understands more than just intonation. Dogs respond to verbal words positive and negative in similar ways in which human brains do check out the study here. h/t BBC
TIP: Dogs look to your left eye for clues. Dogs learn the tempo, phrasing of the language they grow up with. Dogs can hear if your are angry, happy, sad, and tired. Dogs respond as best they can with barks, howls, sighs and laughter. Dogs communicate with felines the same way they "speak" to you. Dog's need water and a well balanced diet to maintain their vocals. Like the human companions, all Dogs do not " speak the same language"