What part of speech is persistent?

"Persistent" can be several parts of speech depending on how it's used in a sentence:

* Adjective: Describing a quality or characteristic. Example: "He was persistent in his efforts to solve the problem."

* Noun: Describing a person who is persistent. Example: "He's a persistent worker."

* Verb (rarely used): To continue doing something despite difficulties. Example: "She persistently tried to reach him on the phone."

The most common use of "persistent" is as an adjective.