What term describes the units added to a base word to create new words?

• A. Base or root words
• B. Idioms
• C. Affixes
• D. Cause

Answer: (C)

Units added to a base word to create new words are called affixes. Affixes come in two main kinds: prefixes, which go at the front, and suffixes, which go at the end. They change the meaning or grammatical function of the word, like turning happy into unhappy with the prefix un-, or turning care into careless with the suffix -less. The other options don’t describe how words are built: base or root words are the word itself without any additions; idioms are phrases whose meaning isn’t literal; a cause isn’t a term for word parts.