Long Vowel Series

Each book in this series introduces only one new grapheme (spelling) for each of the long vowel phonemes (sounds) /ai/, /ee/, /ie/, /oa/, /ue/. The series builds sequentially and cumulatively to include the alternative spelling for each sound, i.e. 'ay, ai, a-e, ee, ea, oa, ie, y, i-e, igh, oo, ow, o-e, ue, ew, u-e.