In order to gain U.S. citizenship after birth, in California or any other state, people may apply for derived citizenship or they may apply for naturalization. Derived citizenship is based on a parent already being a citizen. Naturalization is governed by the Immigration and Nationality Act.
The naturalization process begins with the filling out and filing of the Application for Naturalization, Form N-400. Sometime after the application is filed, the applicant is required to pass a naturalization test that covers ability with the English language and knowledge of U.S. civics.
The English test covers writing, reading and speaking in English. The applicant is required to write out one of three sentences as well as to read one of three sentences correctly in English to demonstrate each of these abilities. Speaking ability is assessed by an officer with U.S. Citizenship and Immigration Services during the eligibility interview. Some people may qualify for exemption from the English test based on age and residency status.
The civics test covers knowledge of the history and government of the United States. There are 100 possible questions, and the applicant will be asked as many as 10 during the interview and must answer at least six correctly in order to pass. If the applicant fails either or both of the English or civics tests during the first interview, he or she may retake the failed portion(s) not less than 60 and not more than 90 days from the date of the first interview. Those who have questions about the process may choose to consult citizenship attorneys for advice. Such an attorney can answer questions about the tests as well as help prepare the Application for Naturalization.Source: "Study for the Test," U.S. Citizenship and Immigration Services, Sep. 20, 2014
Source: U.S. Citizenship and Immigration Services, "U.S. Citizenship", September 19, 2014