This level focuses on contractions where the second word is not. The general rule for this type of contractions is that the first word of the contraction remains unchanged, and then the word not changes to n't. (Such as have not turning into haven't.)

That general rule works for eight of the ten examples found here. The two oddball words are can't (which gets rid of an n) and won't (which would be willn't if it followed the normal pattern). This might be a good time to review the word cannot (which was already featured in level 6-10) as well.