Under the federal Civil Rights law, you can't be denied an employment opportunity because of your birthplace, ancestry, culture, or linguistic characteristics. In other words, it's illegal for employers to discriminate against any employee or applicant because of the individual's national origin. They're also prohibited from requiring employees to speak only English at all times when working, unless they can prove it's necessary for conducting business. If an employer believes the English-only rule is necessary for business purposes, employees have to be notified when they must speak English and the consequences for violating the rule. Any unfavorable employment decision based on breaking the English-only rule can be considered evidence of discrimination if the employer failed to inform employees of the rule. Employers also have the responsibility of providing employees with a workplace free of hostility or harassment. Any ethnic slurs or other negative verbal or physical conduct directed at an individual's nationality can constitute harassment if the offensive behavior creates an intimidating working environment, interferes with work performance, or negatively affects an individual's employment opportunities. Employers may be legally responsible for any on-the-job harassment by their supervisory and non-supervisory employees if they were made aware of the offensive behavior and didn't make an effort to stop it. Under certain circumstances, an employer may also be responsible for the acts of non-employees who harass their employees at work.