Across the world, teachers educated in America, Great Britain, Australia, and other English-speaking countries are being imported in droves to teach the kids of wealthy or even middle-class families of emerging nations in Asia, the Middle East, and other developing regions.

“The majority of the world wants a grounding in English,” said Bruce McWilliams, the executive vice president of International School Services, a New Jersey-based company that recruits teachers for international jobs.

The growth of international schools is staggering. Twenty years ago, there were only about 1,000 English-language international schools worldwide, according to the U.K.-based ISC Research. Most of the students in these schools were the kids of expat families working abroad—diplomats, journalists, NGO staff, technicians, and mid-level corporate types.

Today, there are more than 8,000 international schools, serving 4.5 million students with 420,000 teachers. And 80 percent of students are actually from the school’s host country. And, according to ISC, demand is rising—in the next 10 years, experts expect the number of international schools to double to more than 16,000 schools and 8.75 million students worldwide.

Mitsuko Sakakibara of Japan is a typical parent. Her son Leon, 8, attends the Hokkaido International School in Niseko. “I would like my son to have an international environment education to build his mind as a global citizen from a young age,” she said, explaining she didn’t think he would get that in a Japanese school. “English would be the basic tool to communicate smoothly … and also help to have more choice to decide where to study or work.”

The United Arab Emirates and China now have the most international schools—about 550 English-speaking schools in each, according to ISC—but places as India, Vietnam, Bahrain, and Saudi Arabia are also seeing huge increases. More than 20 cities in the world have at least 50 English-speaking international schools each, such as Dubai (which has more than 250) and Abu Dhabi in the United Arab Emirates; Beijing; Shanghai; Bangkok; Tokyo; Singapore; Riyadh, Saudi Arabia; and Madrid.

The average annual tuition for these schools varies by country—in Bangladesh, it’s $5,200; in Singapore, it’s $18,500. In places like China or India, the tuition is often higher than what the average family in that country earns in a year, making the schools available only to the wealthy.

Recognizing this changing demographic, schools are finding new ways to meet growing demand—and get around rules in some countries that limit the schools local students can attend. Take the Elite K-12 Education Group, which began in Ningbo—located on the coast near Shanghai—and is expanding to Shanghai, Beijing, Chengdu, and other big Chinese cities. The school, which models itself after the British education system, offers an international bilingual program for Chinese nationals. Its local ownership allows local students to attend despite government rules which restrict Chinese nationals from attending internationally owned schools.