Here's a breakdown:
Preposition: When "about" is used to show a relationship between a noun or pronoun and another word in the sentence.
* Example: "We talked about the weather." (Here, "about" shows the relationship between "talked" and "weather")
Adverb: When "about" modifies a verb, adjective, or another adverb, indicating approximation or concerning a topic.
* Example: "She arrived about 7:00 PM." (Here, "about" modifies the verb "arrived" to show approximation)
Adjective: While less common, "about" can act as an adjective to mean "almost" or "nearly."
* Example: "She was about to leave." (Here, "about" modifies the verb "to leave," indicating nearness to the action)
The part of speech depends on how "about" is used in the sentence.