This fourth book in the series introduces long vowel sounds a,e,i,o,u and diphthongs, ou (ow) and oi (oy).
The series presents the long vowel sounds before short vowel sounds. Long vowel sounds are easier for newcomers to distinguish than the short vowel sounds and the r influenced sounds, which are delayed until Book Five.
The sounds are presented with a page each of their common spellings. For example, one page of words with long /a/ sound spelled with a silent e at the end; one page of words with the long a sound spelled with a silent i following the a, and one page of words with the long a sound spelled with y following the a.
Students then see and hear the words in illustrated contexts, with common sentence patterns. Common verbs, and common sight words are presented in these sentences.
Each unit contains a whole language reading selection, based on a short memorized song, chant, poem, or conversation.