John McWhorter on how the English language will rule, but not eradicate, for at least the next 100 years:
“But the days when English shared the planet with thousands of other languages are numbered. A traveler to the future, a century from now, is likely to notice two things about the language landscape of Earth. One, there will be vastly fewer languages. Two, languages will often be less complicated than they are today—especially in how they are spoken as opposed to how they are written.
Some may protest that it is not English but Mandarin Chinese that will eventually become the world’s language, because of the size of the Chinese population and the increasing economic might of their nation. But that’s unlikely. For one, English happens to have gotten there first. It is now so deeply entrenched in print, education and media that switching to anything else would entail an enormous effort. We retain the QWERTY keyboard and AC current for similar reasons.
Also, the tones of Chinese are extremely difficult to learn beyond childhood, and truly mastering the writing system virtually requires having been born to it. In the past, of course, notoriously challenging languages such as Greek, Latin, Aramaic, Arabic, Russian and even Chinese have been embraced by vast numbers of people. But now that English has settled in, its approachability as compared with Chinese will discourage its replacement. Many a world power has ruled without spreading its language, and just as the Mongols and Manchus once ruled China while leaving Chinese intact, if the Chinese rule the world, they will likely do so in English.”
I don’t think you can say Chinese is intrinsically more difficult than the very mixed bag that is English, but the lack of an alphabet certainly makes it less than ideal for a “world” language that will rely more on computers and cell phones than it will on the spoken word.
And another anecdote, from my boss: when he has to meet with sister colleges from China, Japan, and the Philippines, it goes without saying that they’re going to use English as the lingua franca, absolutely never Mandarin or Cantonese.
And it’s not because English is “better,” but as McWhorter points out, it’s sufficient that it “got there first.”
Wet Casements 
I am convinced it is easier for most people to learn English than to learn Mandarin. I am German and since my first language is very similiar to English it was quite easy for me to learn. I never got along in Chinese class though. This language is difficult to learn because the vocabulary is hard to memorize for non-natives, the sounds are unfamiliar and the characters are very challenging. I quit class after half a year.