Dog can understand your word

I know many people get astonished by seeing my post tittle. But I think it is a great curious question for a dog lover and he always want to know whether his dog understand him or not.
If I say that yes dog can understand your word then it will be partially false because a dog cannot understand human language if that dog is not well trained. But observing humans body language like (anger, happy,sad) dog can sense humans word. At the same time if you have the motivation and patience, you will probably be able to teach your dog even more than 100 words.
Driver Dog

When you are a teacher of your dog
Dog can recognize his master by sense his body smell but not his face. That‘s why dog can easily understand a unknown person because his or her body smell is not known for that dog. Dogs are very much happy when his master pay much more attention to him and spend some time with him.a dog can be a humans good friend.

Dog is your best friend