A person who speaks two languages is called bilingual. A person who speaks three languages is called trilingual. A person who speaks more than three languages is called multi-lingual. What is a person who speaks only one language called? Answer: An American BTW: I am an American & the definition now fits me, although circa 40 years ago I spent over a year in Brussels & learned to speak French. I had some difficulty understanding if the speaker spoke at a normal speed & often requested a repeat and/or slower speech.