It's a continent with lots of different countries and ethnic groups.
A person who can speak more than one language is called a polyglot.
More people speak Mandarin than any other language. More places speak English than any other language.
who?
You are bilingual if you can speak more than one language.
Being able to speak more than one language fluently is called being bilingual.
No, it is more appropriate to say "communicate in sign language" as sign language is a visual-gestural language and not spoken.
If you can only speak one language that's fine because it suits the environment that you live in but if you speak more than one language that's even better because you can speak to foreign people and will be able to speak a particular language when you go to a different country.
The official language of Romania is the Romanian language (mother language for more than 90 % of the inhabitants).
Approximately 97% of the population in Spain speak Spanish as their primary language.
Chinese has second greatest number of people who speak it, after English. (Note: While more people speak Chinese primarily than those who primarily speak English, more have English as a primary or secondary language than have Chinese as a primary or secondary language.)
Actually most people in Europe, not just Switzerland, speak more than one language, in fact most countries in the world are that way. America is the weird one in that most Americans speak only one language.
Multiple, as in you speak more than one language