Formal:
* Conversation: This is a general term for a spoken exchange between two or more people.
* Dialogue: This is a more formal and literary term for a conversation, often used in the context of writing or drama.
* Discussion: This term suggests a more focused and structured conversation, often with a specific goal in mind.
* Discourse: This word emphasizes the formal and structured nature of a conversation, often referring to a particular topic or subject.
* Interchange: This term suggests a reciprocal exchange of ideas or information.
* Parley: This word is often used to describe a formal meeting between opposing parties to negotiate or discuss a dispute.
Informal:
* Chat: This term suggests a casual and informal conversation.
* Talk: This is a general term for any kind of spoken communication.
* Exchange: This word suggests a simple back-and-forth of ideas or information.
* Rap: This word is often used to describe a fast-paced and informal conversation.
Literary:
* Interlocution: This term refers to a spoken passage between characters in a play or novel.
* Converse: This word implies a formal and polite exchange of ideas.
* Communicate: This word suggests a general exchange of information.
The best alternative for "dialog" will depend on the specific context of your writing or speech.