I just found this book and I LOVE it! It's called "The Girl's Like Spaghetti" and it's a really fun and effective way to show kids the meaning of apostrophes! For example, the illustration for the sentence "Look, it's behind." shows a girl pointing to the turtle at the back of the race and it is contrasted with an illustration of a boy pointing to the back of a horse with the sentence, "Look, its behind." How fun is that? In this case, a picture is definitely worth a thousand words!
With all the /s/ or /z/ sounds in the book that have morphological meaning, this would also be a great book for practicing articulation and expressive language skills!