1. Noun: This is the most common use. It refers to an object or tool designed for a specific purpose.
* Example: "The new phone is a fantastic device for staying connected."
2. Verb: Less common, but it can be used as a verb meaning "to contrive or invent."
* Example: "The team devised a clever strategy to win the game."
3. Adjective: Very rare, but it can be used as an adjective meaning "ingenious or clever."
* Example: "The detective's device plan to catch the thief was brilliant."
So, to determine the part of speech, you need to look at how "device" is used in a specific sentence.