It's the past tense of the verb "to talk." Verbs describe actions or states of being.
Let's break down why this is important:
* Nouns are words that name people, places, things, or ideas.
* Concrete nouns refer to things you can touch or experience with your senses (e.g., table, dog, rain).
* Abstract nouns refer to ideas, qualities, or concepts (e.g., love, justice, happiness).
Since "talked" describes an action, it's not a noun at all.