You can say 'what's that' in many different ways and a clever dog will react differently for each, even if it's the first time it's heard you say 'what's that?' In a scared tone it'll still react differently while knowing what you're asking.
They even do the cute head tilt when they're struggling to understand something.
I think people vastly underestimate the power of wetware and think animals and us are separated by a chasm, but I think it's a relatively small leap.
We base so much of our understanding of other creatures intelligence on their ability to communicate with us or express things in the ways we do. If elephants judged humans on their ability to communicate in infrasound to speak their names (yes they have names for each other) they'd wouldn't think too highly of us.
Sidenote but the latest I've heard is that elephants like us because they think we are cute.