There are six basic requirements for applying for citizenship:
1) the applicant is 18 years of age or older;
2) five years or three years have passed since the green card was acquired;
3) Continuous Residence and Physical Presence in the United States for a period of time; 4) Maintain moral characters;
5) Civics test of US history and government;
6) Basic English ability.
A permanent resident who satisfies all of these conditions may file a citizenship application (Form N-400) from 90 days prior to the end of the fifth year (three years if he or she acquired the permanent residency as a spouse of a citizen). A particular concern for permanent residents who are spouses of U.S. citizens is that marital relationships must be maintained until citizenship is obtained. If a marriage relationship is terminated because of divorce or separation, it can be possible to apply for citizenship only after five years, not three years, except for victims of domestic violence.
In addition, you must live continuously and practically in the United States two years and six months in five years (one year and six months or more in three years). Even if you are satisfied with your actual residence, you will not be able to meet your continuous residence if you have been abroad for more than one year. If you reside abroad for more than one year, you will be eligible to apply for citizenship after four years and one day after you re-enter the United States.
The citizenship application also contains questions about the applicant's arrest or record of conviction. If you are arrested or prosecuted for drinking or assault and sent to a criminal trial, in many cases your criminal records will be erased after you have been suspended, fined, or educated. It should be noted that even if criminal records are erased, the citizenship application must be marked YES and all records of arrest and conviction must be disclosed.
The interview is a process of confirming your citizenship applications by asking you about the information in the N-400 application, and by testing you on American history and your basic English ability. If you are at the age of 50 (55 years old) at the time of filing citizenship application and have been residing in the U.S. for 20 years (15 years) or longer as a permanent resident, the Civics test can be taken in your native language, and the English test can be waived.
The most important issue in recent interviews is the "legality of obtaining permanent residency" confirmation. If your permanent residency is obtained through your family, you must ensure that all means by which your family has obtained permanent residents have been legitimate.