Camille at BookMoot has a post with a list of children’s books about grammar and words. I have some of these; I want them all. Words can be so much fun. I would add Usborne’s book The Word Detective to her list. (I couldn’t find this book at Amazon or at the Usborne Books website. I guess it’s out of print?)
I really think playing with words should be at least half of teaching good grammar and English usage. Unfortunately, we don’t always get around to the playing part of our homeschooling; we’re so busy trying to keep up with the disciplined learning part. I think playing with numbers should be a big part of math education, too. So someone tell me how to cut loose and play sometimes without losing what little structure and discipline we have in this place. Good books are a start.