What prefix is added to complete words?

There's no single prefix that is added to *all* complete words. Prefixes are added to the beginning of words to change their meaning or create new words.

Here are some common prefixes and examples of how they're used:

* un-: Makes a word the opposite. (happy -> unhappy, do -> undo)

* re-: Do something again. (read -> reread, write -> rewrite)

* pre-: Before something. (game -> pregame, school -> preschool)

* mis-: Wrong or bad. (understand -> misunderstand, spell -> misspell)

* dis-: Not, opposite of. (agree -> disagree, connect -> disconnect)

It's important to remember that these are just a few examples, and there are many other prefixes used in the English language.

Let me know if you have a specific word you want to add a prefix to, and I can help you find the right one!