This document discusses suffixes and their uses. It defines a suffix as a word part added to the end of a word to modify its meaning or usage. It provides examples of common suffixes that can turn nouns into adjectives (e.g. -ful, -ary) or change verbs into different forms (e.g. -ed for past tense). The document emphasizes that understanding suffixes can help students learn new words by recognizing their component parts. It includes activities for students to practice identifying and applying suffixes. Understanding suffixes is important for building vocabulary.