It certainly depends on the dog.
I have two dogs and one clearly understands a certain degree of words, where as I think the other goes off of vibe. I can ask the golden if she wants water in a casual flat tone and she'll look straight at her water bowl and ponder if she does.
Meanwhile, I can say "obbu do booboo?" in an excited upward inflection to the terrier and he thinks he's getting a treat lol.
WHAT