Fissiparous is a wonderful word, best summed up in W. B. Yeats’ The Second Coming: “Things fall apart; the centre cannot hold;  Mere anarchy is loosed upon the world.”

We like to think that English is enlarging into an intelligible whole, that we can speak of people in Singapore or Sedona or Sudan without any loss of understanding.

In fact, English is in a constant state where a local identity is chosen again and again.

One thing that holds us together is the curious fact that the majority use English in addition to their mother tongue and so has a “schooled” kind of English that is more correct than the kind used by natives.

This process began in Scotland in the 18th century during the period that the highlands and islands began to use English in addition to Gaelic, and it is a widely held belief that the best English in the British Isles is spoken in Inverness, a highland city where English came late.

Sometime in the 1950s, English as a mother tongue dropped into a minority of the whole, as the traditional home to English—Ireland, Britain, Australia, New Zealand, and the United States—began to experience lower birthrates in comparison to the additional language communities like Nigeria, Kenya, India, and Malaysia.

The new decade promises more of the same. Larger and larger additional-language English; smaller and smaller numbers speaking it as the mother tongue.

Our country is more multilingual than ever, and, though people (and the media) notice Spanish and ignore the others, we are truly a polyglot country.

In the world, some half a million speak Mixtecs, a language of Mexico. These communities thrive in California and Florida where the language is passed from parents to children. In the 2000 Census, Houston had some 40 percent of households where a language other than English was used. In the 2010 census, the share is likely to be higher.

Torrance High School (in California) has support groups for children who speak Korean and Japanese at home. In “Buffy the Vampire Slayer”—filmed at the high school—there were few Asian highschoolers among the extras. But at Bloomfield Hills Andover (Michigan), high-school students have the opportunity to learn Chinese and Arabic.

Nationally, according to the Census Bureau, 19.6 percent of Americans over five years old use a language other than English at home. Of course most of them use English too—on the outside, at least. In the congressional district that is home to the University of Wisconsin, Madison, the number is just 9 percent. In our congressional district in Ann Arbor, the number is 11.2 percent. In California’s ninth district, where Berkeley is, the number is 36.3 percent.

So it’s not at all surprising that fissiparous English produces new expressions among school children: “Yalla, I’ve been waiting for you for half an hour.” (from Arabic); “Yatta, I’ve found it!” (from Japanese). And you can use these sentences even if you don’t know a language other than English.

English is not falling apart; the center has a strong centripetal force. But the edges spin out into increasing variety.