Why Do Canadians Say ‘Eh’?

Atlas Obscura:

Jack Chambers, a linguist at the University of Toronto, writes that these “ehs” are all of a piece. “All of these uses have one pragmatic purpose in common: they all show politeness,” he wrote in a 2014 paper. Using “eh” to end the statement of an opinion or an explanation is a way for the speaker to express solidarity with the listener. It’s not exactly asking for reassurance or confirmation, but it’s not far off: the speaker is basically saying, hey, we’re on the same page here, we agree on this.