In 1982, Charles Berlitz, one of the post popular linguists and language pedagogues of recent times (although perhaps not the most rigorously scholastic), made the following observation. The numbers and order of languages have shifted somewhat over the last 30 years, but the idea remains the same.
“Among the several thousand world languages, only 101 count over 1 million speakers. Of these, the fourteen most important in number of speakers are, in approximate order,
All of these have over 50 million speakers, including dialects. [Chinese has the most native speakers, but English is more widely spoken worldwide.]
Since most of the world’s population speaks, or is familiar with one of the 14 languages listed above, with one of three other widely-spoken languages – Dutch, Greek, or Swahili – or with a language in either the Scandinavian or Turkic, or Slavic group, it is possible for an individual with the time and inclination to be able to communicate with a great majority of the inhabitants of this planet by learning to speak these 20 languages.”
Wikipedia gives some alternate figures, but the general principle still holds: most of the world’s people speak one of the languages listed above as a first, second, or third language. When one considers that according to the Ethnologue, there are 7,105 known and documented languages on the earth, this makes the challenge of basic communication substantially simpler.
I have experienced this phenomenon myself as I’ve taken trips around the world. Before I had learned Spanish, I was able to hold bilingual conversations using Italian, and got about 65% comprehension. I’ve used German to get by in Bulgaria, and once again Italian in Albania. I have communicated with Russians in Croatian, and also (to my shame) with Slovenians, whose language eludes me despite rubbing shoulders with it for years. All of this, of course, ignoring English, which is used well and widely by so many people. I know Norwegians and Swedes and Finns and Danes and Dutchmen who speak better English than I do, whereas all I can do is look at the ground shamefully, scuff my feet, and mumble “lutefisk” and “Scheveningen.” Well, not quite that bad, but you get the idea.
With the advent of the Internet, the penetration of English is increasing as well, and many countries are beginning to encourage the study of Chinese instead of more traditional languages like French, given the growing presence of China in global trade. I’m up at odd hours of the night (like right now) teaching English to people in Japan, Korea, and China via Skype. For better or for worse, English is on the road to becoming the Esperanto Dr. Zamenhof hoped for, even though it’s devilishly complex and irregular. 
Sadly, the number of languages in the world is diminishing almost daily. The list of endangered tongues in Europe alone is astonishing; languages like Ume Saami in Sweden or Tsakonian in Greece could be gone within my lifetime. Given the massive growth of English and Chinese, as well as the predominance of the above-mentioned languages or language families, this might seem to be less than critical. However, Stephen R. Anderson of the Linguistic Society of America wrote, “When a language dies, a world dies with it, in the sense that a community’s connection with its past, its traditions and its base of specific knowledge are all typically lost as the vehicle linking people to that knowledge is abandoned.”
You can’t really study a language without becoming involved with the cultures and histories of the peoples that speak it. I’ve been a linguist for a long time, and I never stop being curious about new languages, new words, and all the associated things that come with them. While my study of Irish Gaelic (or gaeilge) may not do much to save the endangered language over the long run, it’s taught me more about Ireland and its people than I could have ever hoped to learn otherwise.
If you’re reading this blog, you’re either blessed to speak English as a native tongue, or you’ve put in the hours and become fluent, and my hat’s off to you. But I encourage everyone to learn at least one additional language (for what it’s worth, the more you learn, the easier it gets) to broaden your horizons and increase your awareness of the world.
The Old Wolf has spoken.
[Edit: Click through for two additional charts which shine further light upon the subject.]
 Berlitz, Charles, Native Tongues, Grosset and Dunlap, 1982, p. 6
 If you’re not familiar with Gerard Nolst Trenité’s “The Chaos,” give it a read. Try saying it out loud. I dare you.
 “How Many Languages Are There In the World?”, Linguistic Society of America, 5/2004 PDF File