What do you call someone who speaks three languages?

Trilingual

What do you call someone who speaks two languages?

Bilingual

What do you call someone who speaks one language?

American

I took four years of German in high school, can still sort of read it and understand the general gist of someone speaking it, but could not longer carry on a conversation.

Briefly studied Chinese in college (mostly gone now) and have taught myself a smattering of Spanish.

I almost always dream in English but a while back dreamt I was speaking Vietnamese, a language I know only a few words off.