There is a natural monopoly in a lingua franca, or common tongue. The original lingua franca was a Mediterranean trading language that drew principally on Italian [1]; with modern communications and media linking the world, this monopoly is now global, and the monopolist is English. This became particularly clear to me last year as I traveled the world on a circumnavigation. In Thailand, the signs are in Thai and English. In Singapore, they are in Chinese and English. In the United Arab Emirates, they are in Arabic and English. In Ireland, they are in Irish and English.
English owes its status principally to the political dominance of English-speaking nations—roughly speaking, Britain ruled the world in the 19th century, and America ruled it in the 20th—but it's not a bad choice as languages go. It has a rich technical vocabulary, relatively simple grammar and syntax, and an alphabetic writing system based on the widely supported Roman alphabet. Its only plausible competition is Chinese, due mainly to the massive number of native Chinese speakers, but Chinese writing is so difficult [2] that it's hard to imagine it ever competing successfully with English: although the latter's idiosyncratic spelling is legendary [3], even a mediocre alphabetic system is still much easier than Chinese.
Some people worry that advocating the use of English is an act of cultural imperialism [4], but this issue arises only because for English speakers the native tongue and the lingua franca happen to coincide [5]. It's easy to see the fallacy if you consider the possibility of a different lingua franca; for example, if Swahili were the lingua franca, I would advocate its use, and would strive to master it myself. As luck would have it, I get to be lazy and coast on my native tongue, but if you haven't yet mastered English, it would be much to your benefit to do so.
English owes its status principally to the political dominance of English-speaking nations—roughly speaking, Britain ruled the world in the 19th century, and America ruled it in the 20th—but it's not a bad choice as languages go. It has a rich technical vocabulary, relatively simple grammar and syntax, and an alphabetic writing system based on the widely supported Roman alphabet. Its only plausible competition is Chinese, due mainly to the massive number of native Chinese speakers, but Chinese writing is so difficult [2] that it's hard to imagine it ever competing successfully with English: although the latter's idiosyncratic spelling is legendary [3], even a mediocre alphabetic system is still much easier than Chinese.
Some people worry that advocating the use of English is an act of cultural imperialism [4], but this issue arises only because for English speakers the native tongue and the lingua franca happen to coincide [5]. It's easy to see the fallacy if you consider the possibility of a different lingua franca; for example, if Swahili were the lingua franca, I would advocate its use, and would strive to master it myself. As luck would have it, I get to be lazy and coast on my native tongue, but if you haven't yet mastered English, it would be much to your benefit to do so.
[1] https://en.wikipedia.org/wiki/Mediterranean_Lingua_Franca
[2] http://www.pinyin.info/readings/texts/moser.html
[3] https://en.wikipedia.org/wiki/Ghoti
[4] http://www.catb.org/~esr/faqs/hacker-howto.html
[5] In physics, we would call this a degeneracy.