The Purple Level Books (fifth level) use only decodable regular words based on previously taught letter-sound knowledge, including:

42 main letter sounds and key alternative spellings:

ay as in day, ea as in seat

igh as in high, ow as in low, ew as in dew

oy, ir, ur, al, aw, au, ph, air, ear, are

Rules like “If the short vowel doesn’t work, try the long vowel”

Faint type used for silent letters (e.g., the b in lamb)

Each book also includes:

Tricky words and alternative vowel spellings (inside front cover)

Comprehension questions and discussion topics at the end of each book