Dogs are pretty smart. You can train them to sit or fetch. They know their name. And when you ask if they want to go for a walk? They’re bouncing up and down before you can finish the question.

It may not be the words you use. It’s often your tone of voice or your body language. They can even smell your emotions. 

But some dogs don’t need any cues. They do understand words. Lots of them. Scientists call these dogs “gifted word learners.”