Your employer or potential employer can test your English proficiency (ability to speak or write in English), as long as it tests all applicants. If the employer or potential employer denies someone an employment opportunity because of English proficiency, the employer must show a legitimate, nondiscriminatory reason. Whether or not it is illegal to use the English test will depend on the qualifications of the employee, the nature of the position, and whether the employee's level of English proficiency would have a negative effect on job performance. Requiring employees or applicants to be fluent in English may violate the law if the rule is not related to the requirements of the position or job performance, and it appears that the rule was adopted to exclude individuals of a particular national origin. The Equal Employment Opportunity Commission (EEOC), which is the federal agency that interprets and enforces the laws prohibiting discrimination, has pointed out that the degree of fluency required varies from job to job, even within the same company. This implies that blanket fluency requirements might be illegal, for example, the level of fluency expected from the customer service department is not necessarily the same as that expected from warehouse workers. These rules also apply when a job requires fluency in a language other than English. For example, a company that has a substantial amount of customers who speak only Hindi could legally require that employees who interact with those customers also speak Hindi.