This document discusses common suffixes used in the English language and their meanings. Suffixes are added to the end of words to change the word's part of speech or meaning. Some common suffixes and their functions include -ful and -less to form adjectives meaning full of or without, -ly to form adverbs from adjectives, -ness to form abstract nouns from adjectives, -y to form adjectives from nouns, -er and -or to form nouns referring to people or things, -ics for singular nouns referring to subjects of study, and -ology for nouns referring to subjects of study.