What part of speecj does the word in capital letters play this sentence sliver will tarnish if it is not POLISHED often?

Here's why:

* Action: The word describes an action that is performed on the silver.

* Past Participle: "Polished" is the past participle of the verb "to polish."

* Adjective Form: While "polished" can be an adjective, in this sentence, it's used to describe the action of polishing, making it a verb.