A rule requiring employees to speak only English at all times on the job may violate the law, unless an employer shows it is necessary for conducting business. If an employer believes the English-only rule is critical for business purposes, employees have to be told when they must speak English and the consequences for violating the rule. Any negative employment decision based on breaking the English-only rule will be considered evidence of illegal national origin discrimination if the employer did not tell employees of the rule. See our page on language discrimination for more information.