* Noun: This is the most common usage. It refers to a particular area or part of a country, world, etc.
* Example: "The southern region of the country is known for its warm climate."
* Adjective: It can describe something related to a specific area.
* Example: "They have a regional office in each state."
* Verb: It can describe the act of dividing something into areas.
* Example: "The company regions its sales force based on geography."
So, to determine the part of speech of "region" in a specific sentence, you need to look at its function and context.