Even though US President Donald Trump insists that most Americans speak English, a recent data survey conducted by American Community Survey shows quite the contrary.

The survey published in September, shows that almost half of America speaks a foreign language in America's largest cities.

The survey revealed that in 2017 a record 66.6 million U.S. residents (native-born, legal immigrants, and illegal immigrants) in the age group of five and up spoke a language other than English at home. The number is more than double of what it was in 1990, and almost triple of what it stood in 1980.

As a share of the population, 21.8 percent of U.S. residents speak a foreign language at home — roughly double the 11 percent in 1980.

The survey also highlighted that in the 'other' languages spoken, Indian languages had the top dominance. Of languages with more than 400,000 speakers in 2017, the largest percentage increases from 2010 to 2017 were among speakers of Telugu (up 86 percent); Arabic (up 42 percent); Hindi (up 42 percent); Urdu (up 30 percent); Chinese (up 23 percent); Gujarati (up 22 percent).

Telugu, which had the largest percentage, had 400,000 speakers in 2017. To put in comparison, the population of the United states is 32.57 crore. Out of which, 400,000 speak Telegu as a secondary language.

So what makes Indian languages the fastest-growing ones in the US?

Indian-Americans are the third-largest Asian group in the United States alone or in combination with other ethnic groups, according to 2016 American Community Survey.

There is constant migration from India and at large, South-East Asia. A huge section of this migrant is from Hyderabad - a Telugu speaking majority state. According to BBC, the links are between the city of Hyderabad and the US engineering and technology industries. The rapid growth of information technology in the mid-1990s led to a huge demand for software engineers, he said. Many were recruited from Hyderabad, the biggest Telugu-speaking city. Both Telugu-speaking Hyderabad and Andhra Pradesh, states together now have more than 800 engineering colleges - which facilitates the migration for engineers.

However, despite Indian languages being the fastest growing ones in the United States, most of them still does not feature in the top ten languages other than English spoken in the US - where Spanish tops the list. Even in the most commonly spoken South Asian languages in the US, Hindi ranks first, followed by Urdu, Gujarati and then Telugu.