What part of speech is OK?

"OK" can be a few different parts of speech depending on its usage:

* Adjective: This is the most common usage. It means "satisfactory" or "acceptable."

* Example: "The food was OK."

* Adverb: This is when OK modifies a verb, adjective, or another adverb.

* Example: "I'm doing OK."

* Interjection: This is when OK is used as a short exclamation.

* Example: "OK, I'll do it."

It's worth noting that some style guides prefer to avoid "OK" in formal writing, advocating for more formal equivalents like "acceptable" or "all right."