Letter Sound readers introduce the first 21 letter sounds. These readers have been written using a strictly controlled vocabulary. Text uses only decodable regular words (according to a week by week progression) along with 'tricky words'. Tricky words are words frequently used that are not decodable.Details:MulticoloredSet includes 12 fiction readers, each with colorful illustrations12 Fiction readers introduces first 21 letter soundsInside front shows exact progressionPoint and say page for tricky wordsBright, colorful illustrations