I remember being a sophmore in college and I understood the basics of haskell (not really monads yet) and we worked in groups. My partner was very intelligent, but didn't have a grasp on the language at all.

For the final project, we had a problem that I didn't understand well, but he couldn't use the language effectively. We ended up having him work out the problem incorrectly in a shared notepad and I would refactor his broken code into something that worked. It was a mess. I'm pretty sure I've seen worst things you can possibly build in haskell -- and they are bad.