Canada, eh? / Canadian Gift Sticker

The only usage of eh? that is exclusive to Canada and some regions of Michigan's Upper Peninsula, northern Wisconsin, and northern Minnesota, according to the Canadian Oxford Dictionary, is for "ascertaining the comprehension, continued interest, agreement, etc., of the person or persons addressed" as in, "It's four kilometres away, eh, so I have to go by bike." In that case, eh? is used to confirm the attention of the listener and to invite a supportive noise such as "Mm" or "Oh" or "Okay". This usage may be paraphrased as "I'm checking to see that you're [listening/following/in agreement] so I can continue." Grammatically, this usage constitutes an interjection; functionally, it is an implicit request for back-channel communication.