A word family is the base form of a word plus its forms made from affixes (ex. able, -er, -ish, -less, -ly, -ness, -th, -y, non-, un-, -al, -ation, -ess, -ful, -ism, -ist, -ity, ize, -ment, in-). A base word and related forms support the same core
meaning, and can be considered learned words if students know both the base
word and the affix.
Frequency-based word lists can help expand students’ vocabulary. These lists
contain words that are common in English, but are unlikely to discover in a
random or natural manner. Explicit instruction on word families increases the
number of vocabulary words that can be learned in a limited amount of time.
Word Trees start with a base word and then have all of its related components
added on (affixes).
Example with the word “relate”: