WASHINGTON A growing language divide has opened up across the country, as a sharp increase in the number of Americans who speak English as a second language or don't speak it at all is driving cities and states to respond, often in radically different ways.

In some places, policymakers are enacting or strengthening English-as-official-language laws, barring the translation of certain government documents into any other language. Other places are becoming de facto multilingual societies, with laws and procedures designed to make government more accessible to immigrants who don't speak English. The result is a patchwork of policies that vary greatly from state to state, or even within states.

To date, 31 states and many counties and localities have adopted English as their official languages. Oklahoma became the most recent state to do so in 2010, and many cities or counties have as well, such as Carroll County, Md., in 2013. Just this year, five states Michigan, New Jersey, Pennsylvania, West Virginia and Wisconsin saw pushes to enact official-English laws, although none passed.

But even where official-English laws are on the books, enforcement varies. In some cases, the measures are being ignored as the population of non-English speakers rises rapidly.

"This growing linguistic diversity, that is just simply a reality," said Patricia Gandara, a professor of education at the University of California, Los Angeles, and the author of a forthcoming book, "The Bilingual Advantage."

"The reality is that things are changing," she added. "And this nation is becoming a very multi-language nation."

The U.S. is one of the few countries without a national official language, and the debate over official-English laws has been around almost as long as the country itself. The Obama administration opposes making English the country's official language, which has stymied movement at the national level since he took office in 2009.

The lack of a federal policy hasn't stopped cities and states from acting. Some local and state measures have roots going back more than a century, with many tied to previous waves of immigration or historical events. In 1919, for example, Nebraska outlawed the teaching of any modern language other than English to any child who hadn't yet passed the eighth grade. That law, which reflected the anti-German prejudices of the World War I era, was eventually struck down by the U.S. Supreme Court.

Over the years, circumstances have changed, but many of the arguments have not. Those backing the laws say they preserve cultural cohesion and offer immigrants economic mobility, because learning English is the best way for new immigrants to succeed.

"It's not about language restriction," said Karin Davenport of U.S. English, a group that advocates English instruction for immigrants and backs making it the official language. "It's about a general principle that the role of the government is to teach English, not to be perpetual translator."

By not requiring English proficiency, Davenport added, "you're still providing them with that crutch that's allowing them to remain linguistically isolated."

Yet demographics and the changing linguistic makeup of America have challenged such beliefs. Nationwide, 20.8 percent of residents, or nearly 61 million people, speak a language other than English at home, the U.S. Census Bureau reported last year. In 2000, that number was just 17.9 percent.

In some cases, population trends have prompted government officials to make changes, regardless of what the law says. California law, for example, designates English as the state's official language and requires legislators and state officials "to take all steps necessary to ensure that the role of English as the common language of the state is preserved and enhanced." But the law is largely seen as symbolic, and it doesn't specifically bar the state from translating documents into other languages. Today, the state offers many documents in languages other than English, including an entire Spanish-language version of the state's Department of Motor Vehicles website. As UCLA's Gandara said of the law, "it's completely irrelevant."

"The reality is it's a highly linguistically diverse region," she added. "If you don't speak Spanish or one of the Asian languages, you're kind of left out of the mainstream."

Census data support that line of thinking. Forty-four percent of Californians reported speaking a language other than English at home. In West Virginia, the figure was 2 percent.

That could explain why California has found itself on the leading edge of a debate this year over legislation requiring the translation of patient instructions on prescription bottles. Federal guidelines require pharmacies that receive federal funding to offer some translation services, and some private pharmacies have followed suit to attract more customers.

California would be the second state after New York to enact a law requiring the translations on all prescription bottles. Some worry about inaccurate translations or errors in communicating across languages, but those who support the idea see it as a matter of safety and necessity.

"Obviously the number of limited-English-proficient individuals in the United States continues to grow," said Evan Weibel of Language Scientific Inc., a company that offers pharmacies translation services. "The need for services like this is something that's not going to go away."

Another example occurred this year in Massachusetts, where a concentration of non-native-English speakers in Boston prompted the legislature to allow the city to offer ballots in some precincts in Chinese and Vietnamese. The state has an official-English law on the books, and although the federal Voting Rights Act requires multilingual ballots in some parts of the country, it didn't there.