I've seen this recently and think that this can make a little bit surprise of some.
Language is perhaps the most important function of the human body – it allows us to get sustenance as a child, it allows us to get virtually anything we want as an adult, and it allows us many hours of entertainment through literature, radio, music, and films. This list (in order of least to most spoken) summarizes the most important languages in use today.
10. French - Number of speakers: 129 million
9. Malay-Indonesian - Number of speakers: 159 million
8. Portuguese - Number of speakers: 191 million
7. Bengali - Number of speakers: 211 million
6. Arabic - Number of speakers: 246 million
5. Russian - Number of speakers: 277 million
4. Spanish - Number of speakers: 392 million
3. Hindustani - Number of speakers: 497 million
2. English - Number of speakers: 508 million
1. Mandarin - Number of speakers: 1 billion+
Source: http://listverse.com/2008/06/26/top-10-most-spoken-languages-in-the-world/
I think this list is not accurate (or a very old one) because only in Brazil we have more people than that was listed, plus Portugal, plus Angola, Mozambique would make it already more than 240 millions of speakers (not to mention other small countries that speak the language in Africa and Asia).
my lovely langauge Arabic in the list :)
Arabic is my native language and I can speak English and I know few Spanish. Very good, I can speak with hundereds millions of people :)
I just want to say Chinese are toooooooooo much :D
That list says more about demographics than languages. Mandarin and hindustani are on top because China and India together have more people living than all the rest of the world combined :D