For my first post I'd like to tie together the impending publication of What Language Is with the birth two weekends ago of the world's newest nation, South Sudan. A country like this, full of languages unknown beyond where they are spoken and usually by small numbers of people, is an ideal demonstration of the main lesson of my book.
That is: Human language is always magnificently complex, even when unwritten. The world's 6,000 languages are composed not of a few "real" written languages and a bunch of underdeveloped "dialects," but 6,000 marvels, period.
One of the main languages of South Sudan, for example, is called Dinka. As languages of the area goes, it's a big one: It has about two and half million speakers. However, that's fewer people than live in Chicago, and the language is rarely committed to paper. It's an indigenous language, and one might suppose that it would not need to be as complex grammatically as, say, Russian or Greek.
And it doesn't (although we might ask why Russian and Greek "need" to be) — but it is as complex as them nevertheless. More, really — as is usually the case with small languages. It's the Englishes and Mandarins that are on the easier side as languages go. There is, in short, nothing remotely dinky about Dinka.
Here's a quick slice of Dinka. Let's do plurals. In English, to make a plural you add s: cats, dogs, houses. Now, it's technically a little more involved than that: notice that the s on dogs is actually pronounced z, and that after houses comes not s but ez. 
But there are reasons for that: It tracks very nicely according to what kind of sound there is at the end of the word. The details need not concern us here, but it's an easy three-way split that we all know unconsciously. Add to this a handful or irregular plurals like children and that's the English plural.
So, English is the "complex" language? Here's one singular-plural pair in Dinka:
cup = bing
cups = biiing
So, how do you make a plural in Dinka? It looks like you triplicate the vowel: weird, to us, but not really difficult. In an alternate universe you can conceive of an English where the way to say cups was cuhhhps.
But then, how do you make waal (plant) into a plural? You can kind of tell it's not going to be waaaaaal. Nobody would have time to talk about plants. Rather, waal becomes wal ? you shorten the vowel.
Um, okay. But even then, it's hard to know why biiing has three i's but then while chief is bang, chiefs is baang with just two a's. How do you know whether to duplicate or triplicate?
While we wonder, maybe there's some light at the end of the tunnel with words like the one for hippo. One hippo is a roow, but several hippos are root. So, that looks more "normal." Maybe the regular rule is that you make a plural with —t just like you use —s in English, and those first few are just weird exceptions like mice for mouse.
But no: Girl is nya and girls is nyiir. There's no pattern where you make plurals with t; the hippo word was one more exception. Plus, with nya to nyiir, the vowel completely changes, too. And that vowel thing happens a lot: One thistle is tiil; more than one are tjeel. Sometimes it's about melody, of all things: One palm fruit is tuuk, said on a low tone. Say it in a flutier way, and that's the plural version. And so on.
So, to return to our question: What's the rule for making a plural in Dinka? Answer: there isn't one! You just have to know. It's as if all nouns in English were like man, men and goose, geese.
No one knows just how children learn how to handle this. One imagines that Dinka kids sound cuter than American ones because there are so many ways to make mistakes! In any case, the adults don't, and millions of people speak this language with ease every day, including South Sudan's President Salva Kiir Mayardit.
Dinka is one more example of how the world is full of linguistic miracles far beyond what we learn about in school. We Anglophones think learning two genders in French and Spanish is hard and think of German and Russian's three as sadism. Well, imagine dealing with just trying to say "boys and girls" in Dinka. We saw how user-friendly the girl word is; for the record, boy is dhok but boys is — go figure — dhak.