Although Morgan's answer is correct, it leaves out one crucial point: the dozen is used as an emphasis for "very few," which means "a small, small amount."

A dozen means twelve (12). It is pronounced "duh-zin" instead of "doze-in", just so you're aware. This sentence is talking about eleven or less people. If you ever hear "half-dozen", that means six (6). Hope this helped! Good luck!

All good and correct answers that you can keep adding details to. Notice that it says "fewer than a dozen" and not "less than a dozen". We use "fewer" when there are numbers and counting involved and since "a dozen" means twelve, to be gramatically correct, you need to say "fewer". If you said that "the language is spoken by less than a handful of old people" that would also be correct, since "a handful" is not countable but a mass noun. The French word for twelve is "douze" so I assume that's where the word comes from. And there are twevle months in a year and twelve hours on the clock so I'm sure there's some cosmic connection there as well. Unfortunately, a foot has twelve inches and that can be a pain for any math, although it's not nearly as bad as some other measurements used in the US. But luckilly, there is also "a baker's dozen" which is thirteen: when you go buy a dozen bagels in New York, you better be getting an extra one for free!

"It" is probably a language because it is spoken. A dozen is 12. Fewer is "less than". So, "This language is spoken by less than 12 people." I hope this helps. ;)