If you are looking for a colorful, creative, inticing, captivating and encouraging way to introduce grammar to your child and make it stick, the Explore Language Series by Ruth Heller is be a wonderful series to share with your student.
Behind the Mask: A Book about Prepositions
Cache of Jewels: And Other Collective Nouns
Fantastic Wow and Unreal! A Book about Interjections and Conjunctions