Someone who can speak two languages is called bilingual.
Some common phrases using the word speak are: on (or not on) speaking terms with someone; speak English, speak ill of someone; speak ill of the dead; speak in rhymes; speak no good of someone; speak of the dead; speak no evil; speak out; speak softly and carry a big stick; speak the truth; speak truth to power; speak to me; speak up; think before you speak
Someone who can speak in different dialects is usually referred to as a polyglot or a multilingual person.
nahh
Dead beat
If someone is unable to speak, it's called being 'dumb'.
In fiction (you can't really raise the dead) they call those people necromancers (necro means death or dead etc.)
linguist, polyglot
The word to describe someone who can speak more that one language fluently is Bilingual.That isn't correct, Bilingual means that you speak TWO languages fluently. If you speak five you are PENTAlingual
I think a tri-lingual person.
A monolingual person.
Coroner.