Chinese and Spanish get high rankings out of sheer numbers, but otherwise, English is arguably the most influential language used in the modern world.
You've undoubtedly heard of English-speakers going overseas and finding that a remarkable number of those that they encounter abroad can already speak a respectable amount of English.
I grew up in the States, or in other words, a country where a dominant world language like English is the primary/dominant language. Lately, I've been thinking about what it's like to grow up in a country where there is a very big influence in your own country's language from a a language like English. For example, Germans here use "PC" (Personal Computer) and "SMS" (Short Message Service, or in other words, an SMS is a text message) in their everyday language.
But wait, scratch this entire post. I guess English has plenty of external influences that are now used completely subconsciously. I mean, virtually anything in English ending with "-ble" probably has more or less an exact counterpart in at least Spanish, or French, or both, just as an example. Don't even start me on "Schadenfreude" and "kaputt". Every pasta you eat that doesn't specifically come from Asia has some form of Italian ending on it. And kudzu is a transliterated derivative from the corresponding Japanese word.
Okay, so my argument turns out to be moot. Or maybe I'm really wondering more about growing up in a country where you
actually start learning a second language early on (*ahem*, America, the late onset of your language learning system is bizarre), and you also grow up actually using it to some degree. (Note how many students in America have supposedly studied a language for ump-teen number of years, yet can barely speak it in conversation. This is not necessarily their fault, but the point here is about growing up with a much more functioning second language that you've learned in school that isn't just a letter on a report card).
Anyway, this is probably because English is a bastard language, who mugs other languages in dark alleyways and steals their vocabulary.