A person who does not speak is called mute or nonverbal.
A person who can speak two languages is called a bilingual.
A "polyglot" is someone who knows several languages.
monolingual or unilingual
Someone who can speak in different dialects is usually referred to as a polyglot or a multilingual person.
A person who can speak but chooses not to may be described as nonverbal or selectively mute. This behavior can be attributed to various factors such as social anxiety or personal preference.
mute
quiet
You call them 'mute'.
A person who can speak two languages is called a bilingual.
If you want to call her do it when you feel comfortable but it is always best to speak in person.
If someone is unable to speak, it's called being 'dumb'.
Hysterical.
no you dont
A "polyglot" is someone who knows several languages.
Dial the person's phone number. When the phone is answered, start talking.
monolingual or unilingual
I think a tri-lingual person.