Mick wrote on 05/15/16 at 03:57:56:Harvey Kartel wrote on 05/14/16 at 19:45:55:[The majority of people worldwide can use two (or more) languages.]
In my experience, this is far from true. Most people in the world will not even bother learning another language in their life, since well... they have no reason to for their daily lives (I took on English myself very early because of video games, that weren't widely translated back then).
Mick, this is the entire world we're referring to, not just the parts of North America and Europe that you've visited.

Taking into consideration places like Africa, India, or Indonesia (as I've said in another thread, places that Western media cares little about, but which have a surprisingly huge chunk of the world's populaiton) it becomes understandable that over half of the world's population speaks a second language. I mentioned Africa earlier. In India, where there are over 20 national official languages, anybody whose native language isn't already Hindi (which is the majority of Indians) has to know Hindi, since it's the
de facto lingua franca* of India, and English is highly important in India's job market, as well as being another of India's nationally official languages.
In Indonesia, over 1,000 languages are spoken, no doubt due to the geographically fragmented nature of this country. Bahasa Indonesia is the official language of the country, but most Indonesians aren't native speakers, so... guess what?
Let's not forget about all the people in former Soviet Republics who had to know Russian in addition to their Republic's language. I don't know how much prestige Russian still has in the former USSR outside of Russia, Belarus, and Ukraine, due to it practically being forced upon them by Russia during Soviet times, but I imagine that any ex-Soviet Republic native over the age of 30 or so can speak Russian, and may still use it to communicate with residents of other SSRs. (that's a useful "word" to know in crossword puzzles) Younger citizens may prefer to learn English, but Russian is probably still taught in schools from Estonia to Krygyzstan because historically it's been an important language to unify this 9-million-square-mile region of the world.
Mick have you travelled all over your own country? In France itself, as I mentioned earlier, there are regions where the first language of many is Breton, Catalan, Basque, Alsatian, Corsican, or Occitan. Since they all have to know French, any native speaker of one of those languages is by definition multilingual, in addition to people like you who are native French speakers capable of using English.
In Spain, speakers of Catalan, Basque, Galician, Asturian, Leonese, and Aragonese make up 20% of the country's population; because Castilian Spanish is the only nationwide standard, this fifth of Spaniards must know at least two languages-- Castilian and their regional language. That, and any Spaniard who has learned English, French, German, or another major European language. I'm sure there are quite a few of those-- considering Spain's location in Europe, and the number of British and German tourists the country no doubt gets, I would imagine that these three languages, and possibly Italian or even Latin, are very widely taught in the high schools across Spain.
Italy's pretty linguistically diverse as well. German, Piedmontese, Genoese, Venetian, Friulian, Sicilian, and Sardinian are spoken by sizable numbers, but standard Italian is taught to all of them, as Italy has no other national official language. And as usual, plenty of Italian-speaking Italians are happy to pursue English, German, or French in their high school education, because of how useful these languages are for communicating with the rest of Europe and the world.
Let's also give some thought to the Welsh and Scottish speakers in the UK, or the Irish speakers in Ireland. Frisian speakers in the Netherlands and Germany, Sorbian speakers in eastern Germany, and speakers of any other language in Europe that isn't official at the federal level, whether it's Romansch in Switzerland, Silesian in Poland, Hungarian in Romania/Slovakia/Austria, Sami in upper Scandinavia, or Ruthenian (aka Rusyn) in the Ukraine.
Also, what about China. Over a billion people, and the Chinese language has numerous dialects that are not mutually intelligible. We all know Mandarin is the national standard, but how many Chinese (outside Beijing) are first-language speakers? Cantonese speakers in the south of the country also need to know Mandarin. So do the speakers of Tibetan in Tibet, or the Uyghurs in the Chinese Northwest. I'm guessing hundreds of millions in China can speak two or more languages, because from a speaking standpoint, Cantonese and Mandarian are different languages. They are simply written with the same Chinese characters.
*Speaking of the phrase
lingua franca, any guesses on the literal meaning of this Latin phrase? Yep, that's right. Historically French was a very important language to know anywhere, more important than English. Making it a literal
lingua franca. English probably didn't become the main world language until America rose as an economic superpower within the last century or so. For much of European history, English was looked down upon as a "peasant's language" and this is why even today, English has taken so many words and phrases from French.