General. Except as otherwise provided in paragraph (b) of this section, no person shall be naturalized as a citizen of the United States upon his or her own application unless that person can demonstrate an understanding of the English language, including an ability to read, write, and speak words in ordinary usage in the English language.

Exceptions. The following persons need not demonstrate an ability to read, write and speak words in ordinary usage in the English language:

A person who, on the date of filing of his or her application for naturalization, is over 50 years of age and has been living in the United States for periods totalling at least 20 years subsequent to a lawful admission for permanent residence;

A person who, on the date of filing his or her application for naturalization, is over 55 years of age and has been living in the United States for periods totalling at least 15 years subsequent to a lawful admission for permanent residence; or

The requirements of paragraph(a) of this section shall not apply to any person who is unable, because of a medically determinable physical or mental impairment or combination of impairments which has lasted or is expected to last at least 12 months, to demonstrate an understanding of the English language as noted in paragraph (a) of this section. The loss of any cognitive abilities based on the direct effects of the illegal use of drugs will not be considered in determining whether a person is unable to demonstrate an understanding of the English language. For purposes of this paragraph, the term medically determinable means an impairment that results from anatomical, physiological, or psychological abnormalities which can be shown by medically acceptable clinical or laboratory diagnostic techniques to have resulted in functioning so impaired as to render an individual unable to demonstrate an understanding of the English language as required by this section, or that renders the individual unable to fulfill the requirements for English proficiency, even with reasonable modifications to the methods of determining English proficiency, as outlined in paragraph(c) of this section.

Literacy examination. (1) Verbal skills. The ability of an applicant to speak English will be determined by a designated immigration officer from the applicant's answers to questions normally asked in the course of the examination.

Reading and writing skills. Except as noted in 8 CFR 312.3, an applicant's ability to read and write English must be tested in a manner prescribed by USCIS. USCIS will provide a description of test study materials and testing procedures on the USCIS Internet Web site.