What part of speech is the prefix un?

The prefix "un" is not a part of speech on its own. It's a prefix, which is a word part that is added to the beginning of a word to change its meaning.

Here's how it works:

* Prefix + Base Word = New Word

* un + happy = unhappy

The prefix "un" often creates the opposite meaning of the base word.

To determine the part of speech, you need to look at the whole word that the prefix is attached to. For example:

* unhappy is an adjective.

* undo is a verb.

* untie is a verb.