Oklahoma constitution
Article XXX: official actions of the state of oklahoma
Section 1

As English is the common and unifying language of the State of Oklahoma, all official actions of the state shall be conducted in the English language, except as required by federal law. No person shall have a cause of action against an agency or political subdivision of this state for failure to provide any official government actions in any language other than English. Nothing in this Article shall be construed to diminish or impair the use, study, development, or encouragement of any Native American language in any context or for any purpose. The Legislature shall have the power to implement, enforce and determine the proper application of this Article by appropriate legislation.