Grammar/Punctuation.

Hi, I am but a simple tradesman, and didn't fare too well in school, and don't write. I do read a little, but my question arises more from contact through social media networks. When the youth of today write a sentence/ make a statement, (also used in speaking), it usally ends in either "eh", "ay" or "right". Even though they do not neccessarily mean it as a question, should there not be a question mark at the end?
eg; "we should go out ay", "I know right", "that was good ay"
Thanks for your help with this,
Chris.