Build words with your tri-blocks tub and learn short vowels, long vowels, adjacent consonants, split digraphs, multi-syllabic words and adding suffixes. Turn each tri-block and manipulate the middle sound (CVC, CVVC), change a blend ('sp' to 'sl' or 'st'), or change the spelling (y to i) when adding a suffix. Tri-blocks let you know the spelling rules by their color-coding and their systematic phonics progression. Unique connector block included for building multi-syllabic words. Contains: 90 color coded blocks and teaching guide.