what does prefix un mean
The prefix UN means can't do something. Like for example Unable, She is unable to do it > She can't do it. The prefix UN means can't do something. Like for example Unable, She is unable to do it > She can't do it.
A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix un- is added to the word happy, it creates the word unhappy. Particularly in the study of languages, a prefix is also called a preformative, because it alters the form of the words to which it is affixed.