A list of words.
In grammar school I had to memorize a whole new list of twenty words every week I hated it because my memory isn't all that good, but my mom would sit me down and quiz me, quiz me, quiz me until I finally got them all. I'm glad she did, though, because it means I have a pretty good vocabulary now. For me, the really difficult part wasn't remembering the words themselves, but the quirky spellings.