But do you have to be fluent in English to be able to compete with programmers around the globe and be successful?
color instead of colour
center --------> centre
math ----------> maths
And then these new-fangled languages [like Crystal] come along and add to the misery with their:
fiber ---------> fibre
Usually [with UK layout anyway] ALT+E followed by the vowel you need will give you an accent on that vowel; acute on E, umlaut on O and U, etc.
I use Irish layout which is the same as UK but has the additional advantage [for the languages I need to type] that I can type acute accented vowels with just ALT+vowel: áéíóú ÁÉÍÓÚ Thus saving an extra keystroke. Some other handy ones:
ALT + s gives you German ß
ALT + n followed by another n gives you Spanish ñ
ALT + c followed by another c gives you French ç
ALT + ! gives you Spanish ¡
[oddly, on my keyboard ALT + ? doesn't give the Spanish upside down question mark, but a division sign]
ALT + g gives you copyright symbol ©
ALT + r gives you registered trademark symbol ®
ALT + k gives you a degrees symbol ˚
ALT + t gives you square root symbol √
ALT + y gives you a Yen [?] symbol ¥
ALT + f gives you a florin symbol ƒ
ALT + h gives you a mu symbol µ
ALT + l gives you pi π
etc. etc.
I have worked on a large system for a multi-national drug manufacturer. Some modules were written by Spanish speakers, others by Germans, a few by French and about half by English speakers. It worked well. The only real problem was that variables and function names were all in their respective native languages. At least the module names were all in English (well sort of). I ended up maintaining it because I spoke all those languages (badly) and was willing to use various dictionaries. It was an experience!
In my experience the vast majority of books and internet resources are in English as are the keywords in most programming languages. If you can read English at high school level you should be Ok.
Since programming relies on teamwork, you need to speak the local language well wherever you live and work.
Myself I think doing proofs in geometry class was the best preparation for being a developer. Most of the people whom I have known, and whom I believed were very good or excellent developers loved their geometry class. That is not proof, just an observation.
Really almost any profession you should (not need) to be able to read, write and do arithmetic. Public speaking is useful too.
You will most likely need to read some technical information in English.
You will probably need to write a question in English to solicit help.
You might find a job working with others who do not speak your language.
Having said that, I have seen where English is considered a 'Common' language. The tourism industry seems to have this requirement.
I know a couple, one person is German and the other is French. They live in France. Neither spoke (past tense as they do more so now) the other language. At a party someone asked how they communicated with each other. "English" of course, the common language. The German is able to work in France because of her ability to speak English enables her to communicate with co-workers.