* Verb: This is the most common usage, referring to performing an action.
* Example: "The magician acted out a funny routine."
* Noun: This refers to a single performance or a part of a play.
* Example: "The first act of the play was a bit slow."
* Adjective: This is less common, meaning "done intentionally" or "having the quality of acting."
* Example: "His act of kindness surprised everyone."
Let me know if you have a specific sentence in mind and I can help you identify the part of speech of "act" in that context.