U.S citizens can be native-born, foreign-born or naturalized. Naturalization is the process by which permanent residents become U.S citizens. The U.S citizenship is a long and exhausting process, but is well worth the time and effort. To apply for U.S citizenship (Form N-400), you must meet the following requirements:
Age: You must be at least 18 years of age to apply for naturalization using Form N-400. If you are not yet 18 years of age, and wish to apply for the Naturalization process, you must apply using Form N-600 (Application for Certificate of Citizenship).
Permanent Residency: You must have resided in the U.S as a legal permanent resident (Green card holder) for the past 5 years. You can also apply for Naturalization process when you have 3 months left to complete the 5 years requirement (at 4 years and 9 months). This residency requirement differs for applicants who have obtained their Green card by refugee status, U.S military personnel and spouses of U.S citizens.
Physical Presence and Residence: You must be physically present in the U.S for at least 30 months out of the 5 years prior to applying for naturalization. You must not have been outside the U.S for more than 6 months in any given year. You must have lived in the state or district of the USCIS office in which you applying for your naturalization process for the past 3 months prior to applying.
Moral Character: This means you must have paid your taxes regularly, must not have been involved in any illegal activities and should have no criminal record. Applicants are required to disclose all relevant facts to the USCIS while applying for naturalization including criminal history.
Language: You must be able to speak, read and write in basic English. You maybe exempted from this requirement if
You are 55 years of age and have been a permanent resident of the U.S for the past 20 years,
You are 50 years of age and have been a permanent resident for the past 15 years,
You have a permanent physical/mental impairment that prevents you from learning the English language.
Knowledge of U.S history and the Government: You must have a basic understanding of the U.S Government and the history of the country. You will have to take an oral test about these topics at the naturalization interview. You will be exempt from this test if you meet the conditions for English language exemption as well.