General:
* Says
* Utters
* Talks
* Communicates
* Expresses
* Articulates
* Pronounces
Formal:
* Eloquates
* Declaims
* Orates
* Enunciates
* Delivers
Informal:
* Chatters
* Rambles
* Whispers
* Mumbles
* Shouts
* Yells
Specific to language:
* Converse (in a language)
* Addresses (in a language)
* Discourses (in a language)
To choose the best synonym, consider the tone and context of your writing.