No native speaker would add "at" in the end of this question.

oh yes they do, unfortunatly - all the time. (including me :)

Seriously? 😊

Oh yeah. That's one of those things that isn't considered correct, yet almost everybody does it. It's like your Russian чё. I was once chatting with this Russian woman on Skype and she was telling me never to use that word. Then her daughter called her from another room, and she yelled back "Чё"! 😭

😂👍