I was at a Los Angeles area middle school teaching Spanish to a group of 7th graders just learning about the language. We read that Spanish was the third most spoken language in the world. So I asked them what they thought number 1 and 2 were. We agreed English probably had to be one of those, but the other was a stumper for them. Several students raised their hands. "Armenian" was their response. I asked one of them why Armenian. "Because everyone I know who speaks English also speaks Armenian."
I told her she needed to consider the whole world, not just where she lives.
Another student tried something else. "Persian?" he asked, a little more hesitant.
"No," I said, "I'm sure it isn't Persian. Do you know a lot of people who speak Persian?" He nodded. I called on a third student.
"Russian?" There was a community of people in this neighborhood who had immigrated from Russia. But at least this was a closer guess, Russia being a country with a huge landmass, although not a huge population. I was amazed at the students inability to think about languages outside of their own experience. So although I also did not know what the two most spoken languages were, I tried to help them think about the large world, about what they knew of populations and country size, and we eventually all agreed it was probably English and Chinese (Mandarin) or maybe a language from India.
Everyone talks about how small the world has become with the advent of the Internet, still, when it came down to engaging that world a group of 7th grade students couldn't evaluate their own place in it. It worries me, but I'm not going to solve it in one day of subbing. It's a problem as old as time, being unable to imagine a universe that doesn't revolve around your place in it.
What's your guess? You might be more right than you think:
About.com geography lists these most spoken languages from 2007
1. Mandarin Chinese - 882 million
2. Spanish - 325 million
3. English - 312-380 million
4. Arabic - 206-422 million
5. Hindi - 181 million
6. Portuguese - 178 million
7. Bengali - 173 million
8. Russian - 146 million
9. Japanese - 128 million
10. German - 96 million
But here's another site that explains the complications of coming up with any real data and offers a list of interpretations: http://www2.ignatius.edu/faculty/turner/languages.htm