Depends. English first language countries remain mostly monolingual. But the rest divides into:
- educated people are expected to learn English in school and end up consuming English media anyway (where you'd expect >50% multilingual, but not everyone)
- country has many official languages (many people are multilingual, but not necessarily in English; e.g. India, Indonesia, possibly China)
- country has literacy problems (not so many left now, maybe in sub-Saharan Africa)
- proud monoglots of a language that isn't English: Japan, France (but even here a lot of people consume English media anyway)
Belgium has 3 languages but my guess would be that each region speaks English better. The French, pardon, Walloniers scarcely speak Dutch and while the Flemish area speaks better French it's usually not great (unsure whether most people would qualify as fluent). Afaik Flanders has mandatory French in school but Wallonia doesn't need to take Dutch, even though 60% of the population is Dutch-speaking. The German-speaking region is mostly forgotten about and they either integrate with the French-speaking part or work in Germany with Belgium as a cheap place to live
The Netherlands has Papiamento as the native language of most people in a part of the country. They're overseas but they vote for the same government and live by the same law. I literally didn't know this until a few years ago (I'm 30). I assume they don't want independence due to things like getting defence and other benefits from a much larger economy (and we're right to feel the need to pay such repairs) but man, this feels really 1800s slave trade levels of wrong. Not a soul speaks Papiamento in the european Netherlands, it's not even an option in school — let alone compulsory!
In Luxembourg it's hit or miss whether someone speaks the national language (Luxembourgish), French (an administrative language), or German (another administrative language). Many will speak at least two, but many also only one (French in particular)
Very eurocentric perhaps but that's my experience with countries that have more than one official language: nearly nobody bothers learning the other if there is no direct necessity
- educated people are expected to learn English in school and end up consuming English media anyway (where you'd expect >50% multilingual, but not everyone)
- country has many official languages (many people are multilingual, but not necessarily in English; e.g. India, Indonesia, possibly China)
- country has literacy problems (not so many left now, maybe in sub-Saharan Africa)
- proud monoglots of a language that isn't English: Japan, France (but even here a lot of people consume English media anyway)