What part of speech is knocked?

"Knocked" can be a few different parts of speech depending on its context:

* Past participle: This is the most common usage. Example: "The door was knocked open."

* Verb (past tense): This is used to describe a completed action. Example: "He knocked on the door."

* Adjective: This is less common, but can be used in specific contexts. Example: "He had a knocked knee."

To determine the correct part of speech, you need to look at the sentence and how "knocked" is used.