EEOC Sues Employer for Maintaining an English - Only Policy
A rule banning other languages will often be discriminatory, according to EEOC, but can be used in very specific circumstances. If it is communicated in advance and narrowly tailored to meet business necessity, it's possible to implement one without running afoul of the law, experts say. But even then, employers who adopt these policies should be sensitive to the needs of staff members.
Mike Studenka was quoted in an article on HR Dive.