Formal:
* Monologue: A long speech by one person, especially in a play or movie.
* Soliloquy: A speech by a character in a play, delivered while alone on stage, revealing their thoughts.
* Address: A formal speech directed at a specific audience.
* Lecture: A formal talk on a specific subject.
* Presentation: A structured talk delivered to an audience, often accompanied by visuals.
Informal:
* Speaking: A general term for the act of using words to communicate.
* Talking: A casual term for speaking.
* Conversation: When two or more people talk together.
* Dialogue: A conversation between two or more people, often used in literature or film.
Specific situations:
* Testimony: A formal statement given by a witness in court.
* Declaration: A formal statement, often made in a legal context.
* Report: A formal account of a situation or event.
The best word to use will depend on the specific context and the type of speech being made.