According to a Brookings study, English proficiency is an essential gateway to economic opportunity for immigrant workers in the United States, but nearly one in 10 working-age U.S. adults—19.2 million persons aged 16 to 64—is considered to have limited English proficiency (LEP).

Working-age LEP adults earn 25 – 40% less than their English proficient counterparts. While less educated overall than English proficient adults, most LEP adults have a high school diploma, and 15 percent hold a college degree.

The size of the working-age LEP population is more than 2.5 times what it was in 1980, and the LEP share of the U.S. working-age population has almost doubled from 4.8% in 1980 to 9.3% in 2012. In Miami and Los Angeles LEP adults represent about a quarter of the working age population. San Francisco is the only other metro area. In New York City, about 18%.

There are shortages in English as a second language education, as evidenced by long waiting lists for instruction.

Brookings recommends:

• Increase funding from the Workforce Investment Act, the main source of federal funding for adult education, and more funding at at the state and local level
• Increase employer-initiated English education programs
• Innovate instruction at the worksite, online, and by mobile device.

The leading certifications for teaching English as a second language to adults in the U.S. are TEFL (Teaching English as a Foreign Language) and TESOL. My partner Rilla Murray obtained a certification in the Cambridge University program, CELTA (Certificate in Teaching English to Speakers of Other Languages).