If you could instantly become fluent in any foreign language which one would it be?

You say that, but as a native English speaker, I find Spanish is easier to get to grips with than French (Spanish seems a bit more relaxed with the whole Masculine / Feminine malarkey and I find there are no where near as many rules and /or prefixes.

Currently studying French and Spanish... I would also like to learn Portuguese and Italian, as they should be relatively easy once I'm fully competent in Spanish... but not until I've reached a notable standard to avoid confusion and (literally) mincing my words lol

Maybe not now...but who knows where we'll be in, say, 20-30 years time? You have to think about big and fast the Chinese economy has grown in the past 20 years alone (e.g. at the start of the Millennium, their automotive industry was pretty much the laughing stock; now, with BYD in particular, they're leading the world for electric vehicle manufacture) .

China is well on course to becoming a single superpower to rival USA; so it would make sense to learn Mandarin from business perspective & there are even celebrities whom you wouldn't typically associate with the language now learning / speaking it including:- Mark Zuckerberg; Kevin Rudd; Vanessa Branch; Mira Sorvino and Mark Henry Roswell

I know, and I would probably want to learn Mandarin; but I'm not familiar enough with that to know certainly whether I'd want to learn Mandarin or Cantonese.

Dog. So I could speak with dogs.

Probably French or Spanish, trying to think of the most widely used languages across the world

Arabic and Mandarin?

Probably French or Spanish, trying to think of the most widely used languages across the world

Can include English if English is not your first language.
I'm excluding languages as Lorem Ipsum, sarcasm, punning, slang, trolling etc
Only name one language 🤷🏾*♀️.

Well blatantly English is the most widely spoken language in the world; I think it's (unofficially) the Global language... go to pretty much any city / significant town on the planet, and you shouldn't have to work too hard to find an English speaker there.

However, if you're looking for the languages with the most native speakers, then Chinese (Mandarin) and Spanish are both spoken way more than English.

Check this list out... there's a few surprises there; I guess I should've guessed Hindi would be right up there; it's the one language spoken throughout India... as well as the local languages (e.g. Guajarati Tamil etc.) , but I would never have put French so far down that list; Sacre Bleu

https://en.wikipedia.org/wiki/List_of_languages_by_number_of_native_speakers

German!
how many languages do you guys know? I know Spanish and English fluently
(Born in Spain, live in England, I love Germany)

Can include English if English is not your first language.
I'm excluding languages as Lorem Ipsum, sarcasm, punning, slang, trolling etc
Only name one language 🤷🏾*♀️.

Do you think that I am fairly fluent in English? Japanese and Spanish are the languages I would live to speak fluently. Latin comes as third.

I have no idea whether you’re fluent in English or not.

To be at that level, I need at least B1, possibly even B2. C1 is fairly at mother tongue level. English is not the language I was grown up with. Do you at least think that I am good at that language?

Either Japanese or German

Can include English if English is not your first language.
I'm excluding languages as Lorem Ipsum, sarcasm, punning, slang, trolling etc
Only name one language 🤷🏾*♀️.