Let’s turn it around. Can humans really know what dogs are saying to us when they use certain sounds to communicate? No one else may know what my dog is saying because they don’t speak the same language as he and I do.
But you can sure tell scared, sad, defensive, and happy from what dogs vocalize . Good point.
My 95 pound bundle of love Rotten Shepherd and I communicate well. When she has to go out, she licks my hand. When she thinks it's meal time, she'll stare at me until I get the message.
She knows what "walk" means, and "it's time to wake the boy up" when our grandson spends the night.
Yesterday, she wore herself out watching over our 6 MO granddaughter, who spent the day with us. You should have seen her jump into action when she heard her crying...she rolled over on the trampoline, and didn't like that one bit.
It was a great day for me, I was able to hold my granddaughter for 90 minutes uninterrupted while she napped.