With a few exceptions, words with prefixes and suffixes are spelled as one word whether they are nouns, verbs, adjectives, or adverbs, and function accordingly. Common prefixes and suffixes include anti (antiwar), bi (bilingual), co (coauthor), counter (counterclockwise), extra (extrasensory), inter (intercollegiate), intra (intramural), mid (midlevel), multi (multitasking), neo (neorealism), non (nonbeliever), over (override), post (postwar), pre (prefabricated), pseudo (pseudoscientific), re (reexamine), semi (semiconductor), sub (substandard), trans (transatlantic), un (unexamined), and under (undervalued).
Be aware that some computer spell‐checkers may direct you to insert hyphens after these prefixes. Check a dictionary; if the word is not there, it is customary to use a hyphen in the following situations:
The second element is capitalized: anti-British, mid-Victorian (but transatlantic).
There might be confusion with another word: recover vs. re-cover, or recreation vs. re-creation.
The second element consists of more than one word: non-church-attending.
The prefix ends with the same letter that begins the root word: anti-intellectual (but reenter, reexamine).