Prefixes are pretty neat linguistic tools that we use to modify the meaning of words. They are those little word parts you add before the base word to create a new word with a slightly different meaning. For example, adding the prefix “un-” to the word “happy” turns it into “unhappy,” meaning not happy. Some other common prefixes include “re-” (meaning again or back), “pre-” (meaning before), and “bi-” (meaning two). Prefixes can be a lot of fun to play around with and can help expand your vocabulary.