It's not a simple thing, and what will likely happen is language balkanization for a significant period of time before any seismic shift from English to Chinese which is unlikely to happen for a number of reasons regardless.
China is heavily investing on Africa, so I would not be impressed if Africans start learning Mandarin more actively than they do now. African population is the one experiencing the fastest growth at the moment.
In the Americas, I would expect things to remain more or less the same.
Historically, the Chinese have been very hermetic when it comes to foreign policy. Chinese yuans (RMB) are not as liquid as dollars, and that seems intentional as they want to keep tight control of their currency value. But they do seem more expansive recently... opening overseas military bases in Djibouti, etc.
The following report from the French ministry of education from 2014 (in french unfortunately) [1] states that in Europe, 94% of the students study english as a foreign language (high school and university). Then comes French (23%) and German and Spanish (19% each).
As for Brexit, I don’t think english is used as the main working language in the EU because of the UK’s infuence, just because it is the foreign language most people speak.
[1] http://www.education.gouv.fr/cid74880/l-apprentissage-des-la...
From my own experience (I speak/write in 5 different languages and live in Germany since 2011), it takes between 5 to 10 years to learn German minimally. Other Western European languages are simpler to learn and more popular: Spanish, English, Portuguese, French.
Much of the difficulty is not at knowing the German vocabulary and pronunciation. It is simply that the language is very strict in its written and spoken form. By comparison, other western languages had global exposure over the centuries and today are fitting like a shoe to the native speakers of other languages, so the learning curve is far less steep.
As a Norwegian, I found German far easier to learn than English, French and Spanish.
English: "My wife sent me an email", but "My wife sent an email to me".
Yes, very obvious :)
To your second point, Latin inflections are for the most part very mechanical, even for verbs. Latin is difficult to master due to the fact that it's for the most part only read. It's far easier to gain fluency if you develop an active vocabulary through speaking and writing.
If you are looking for objectively hard things to master I would pick German noun gender or Japanese Kanji. They both require rote memorization of thousands of items. Both have relatively weak patterns to cut down the amount of cases you need to memorize.
That's not true. The republic of Ireland and Malta (and possibly more) still have English as an official language.
Now there's a funny game of chicken to see if one of them will blink and switch to requesting English in the EU: https://www.politico.eu/article/english-will-not-be-an-offic...
But as a matter of practicality, I'm sure English will continue to be used as a working language across European institutions.
Cixin Liu's "Three-Body Problem" sci-fi novel is pretty popular and is being made into a movie[1] this year. And some Chinese musicians, like Faye Wong, have been well-known in the the west for many years.
So while American, Japanese and Korean entertainment is much more dominant, I don't think that's an entirely fair statement.
Spanish is on second place with the most native speakers, then comes English in third position and Portuguese on sixth from the European-based idioms: https://en.wikipedia.org/wiki/List_of_languages_by_number_of...
China tops that list, no wonder if they also produce a higher volume of literary works on their native language.
I would say it started 50-60 years ago at most.
That is true... but only 10% of Indians can speak English. It might appear higher because visitors are likely to remain in urban or tourist-y areas, where the percentage of English speakers is much higher.
I think what you're thinking about is when English supremacy started, that can probably be dated to the post-WWII world when the US economy was far ahead of everyone else for decades.