According to the Equal Employment Opportunity Commission (EEOC), the agency that enforces many federal anti-discrimination laws that cover the workplace, about 17.6% of the population spoke a language other than English as of 2000.
Due to the rise of diversity, many employers started implementing English-only workplace policies to stop their employees from talking in languages other than English. Sometimes the policies required employees to speak English at all times on the job, or they required them to speak English while performing specific tasks.
These policies are controversial and may be motivated by xenophobia. In general, they discriminate against employees who have foreign backgrounds who may not be comfortable speaking in English at all times. Title VII doesn’t explicitly prohibit discrimination on the basis of native language. However, the EEOC does take the position that English-only policies tend to discriminate against workers on the basis of their national origin, which is a Title VII violation.