Give the dog commands confidently and with high intonation. It will absolutely understand notes of uncertainty and doubt in your voice. Dogs without difficulty understand how sincere person is and your attitude to people. It's easier for a dog to understand a person, but people don't always understand dogs.
Focus on the tail
Raised up tail means the dog has a wonderful mood. Thus, it expresses its joy. If the tail is under stress, the pet is ready to fight and win. Down and no-load tail means calm state and normal mood. Smooth movements of the tail from side to side express smile. Sharp ups and flaps mean elation. When the tip of the tail moves, it expresses apologetic behavior. The tail between legs shows dog's fear. The more it touches the belly, the more fear it has.
Signals from the ears
Ears tilted forward show dog's concentration. If the ears touch their back, then we can talk about the great sympathy of the animal. Ears pulled back show the dog is ready to follow orders. It's ready to obey you.
What will the lips tell?
Forward lips say about dog's fearless. Lowered edges of lips show fear of the animal. This state of the lips with a noticeable grin expresses its willingness to attack. Emotional dogs can smile that speaks of their joyful mood and love to you.
Acoustical signals
Dog's gumbling shows the expression of affection and threatening behavior. You will immediately know what this sound means. If it trusts you it grumbles combining it with haptic contact. It may put out its paw, nestle its forehead against you or tickle you with its nose.
If the animal growles and clearly shows its teeth, such behavior serves as a signal to attack. In such a state the dog may bite.
Bowwow can also express different emotional state. If this happened once the pet just wants to be noticed. Loud bowwow means close danger.
Its whimper means fear and uncertainty. If it's lonely and sad, you will hear under yawl. Whining shows its please.
In general, different breeds of dogs express their emotions differently and written guidance won’t help you a lot here. You have to give your ear to your pet and take into account its wishes and behavior.