Start over?

Is it possible to start over? I would like to clear my information and start afresh.

Sure. You can reset a language in your Language Settings - Login - LingQ

I tried deleting my Korean data. It doesn’t seem to be working. Is there a delay? Should I not use the app for an hour or something?

Looks like there is a bug at the moment. I asked developers to look into it. We will have it fixed!