Direct derivatives:
* Talker
* Talkative
* Talkativeness
* Talking
* Talks
Words with related meanings:
* Chat
* Converse
* Discuss
* Debate
* Dialogue
* Gossip
* Harangue
* Lecture
* Orate
* Speak
* Tell
* Verbalize
* Communicate
Less direct, but still related:
* Talking point
* Talk show
* Walkie-talkie
* Talk therapy
* Talk to the hand (idiom)
This is not an exhaustive list, but it gives you a good idea of the variety of words that are related to "talk".