Prefixes and suffixes are letters added to words to change their meaning. Prefixes come before the root word, while suffixes come after. Some examples of prefixes and suffixes and how they change the meaning are provided, such as "pre-" meaning "before" and "-less" meaning "without." Root words are the base words that prefixes and suffixes are added to in order to form new words. Some online games are suggested for practicing adding prefixes and suffixes to root words.