SYNTAX:
speak [in] <language>
Lets you talk in the language of your choice. Of course, you'll have to know the language too. If <language> is not a spoken-only language, you will also write in it, unless you use the "write" command afterwards. If it is a spoken-only language, the language you write in will stay the same as whatever it was.
speak
Tells you what language you're currently speaking in, and what language you're currently writing in.