Although I'm not a native speaker of English I can't help but feel that English will remain the common language for quite some time. Any new technology is first 'released' in English. Be it new devices or even new programming languages. Actually, I personally don't know of any programming language that isn't based in English (i.e. logical sentence structure etc.) and mainly, the documentation for practically anything technical/technological is essentially in English.

Sure, you've got user manuals in multiple languages, but for chip specification, pin diagrams or anything really, I am unable to find manuals in a non-English language. I believe, the same thing applies to other Engineering fields too. Sure, you've got formulae that's universal. Say, you're a Mechanical Engineer working on some modeling-simulation software, you'd be hard pressed to find a non-English version.

And seeing that most of the world is embracing technology, even in the smallest capacity, I feel English isn't going anywhere.

I think China's ascendancy is a foregone conclusion, but not the dominance of Mandarin.

I think the easy part of China's ascendency has just about finished, a lot of very hard economic, political and demographic problems are about to kick in, I wouldn't presume that their continued meteoric rise is guaranteed.

I honestly do not - I fear for China.

Over the past 150 years this past generation is the only one not to suffer some horrific war, genocide or starvation. China has a revolt somewhere almost daily, it has none of the institutions we are pretty sure are necessary to managing power (independent judiciary, enforceable contracts etc) and has worrying signs of becoming a mafia state, with none of the benefits of one guy in charge ala Putin .

So basically there are a huge number of ways it can go wrong, very little to hold it together except the fear that if we don't keep on this course it will be a lot worse.