What about dual citizenship?

This arises when a person is considered a citizen of two or more countries at the same time. The United States does not favor the concept of dual citizenship and, in fact, when a person is naturalized in the United States, they are required to renounce any and all other citizenships which they may have. However, there are situations when a US citizen can also be a citizen of another country. This usually occurs in cases where the foreign country does not require its nationals to renounce its citizenship when that person is naturalized in the United States, or where a person is born in the United States of parents who are nationals of other countries, which base their citizenship on parentage. Thus, in such a case, the person is a citizen of the United States by birth in this country, and a citizen of the foreign country by virtue of the nationality of the child's parents.

As mentioned above, the second method to obtain US citizenship is through naturalization. In order to be naturalized, the first requirement is that the applicant be a lawful permanent resident of the United States. An exception exists for those who served honorably in the US armed forces in times of war.

The second requirement is that the applicant must be at least 18 years of age at the time of filing the application for naturalization. Again there is an exception for those who served honorably in the US military during times of war, as well as for minors who have at least one US citizen parent who petitions for them.
The next prerequisite is that the applicant must have satisfied certain residency requirements. Initially, the applicant must have been physically present in the US for at least half of the required residence time preceding the date of filing the application. The statutory residence time is five years, unless naturalization is based on marriage to a US citizen in which case it is only three years. (In this situation, the alien must have been a resident for at least three years and must have been married to, and living with, the US citizen spouse for at least the preceding three years). A person is permitted to file their application for naturalization three months prior to meeting the physical presence requirement.
In addition to the above, an applicant must not have abandoned their residence in the United States. If a person remains outside the United States for one year or more, then they have broken their continuous residence for naturalization purposes. It does not matter that the person had permission to be outside of the US, such as with a US re-entry permit. The only exceptions are for those serving in the US armed forces, with certain US government agencies, as religious workers, or with certain international groups. In these cases, the applicant must have filed an application to preserve residence for naturalization on immigration form N-470. This application can only be approved if the person had been physically present in the US, as a permanent resident, for at least one year, prior to filing the application, and it must be filed before the person has spent one year abroad. If the applicant is absent for more than six (6) months, but less than one (1) year, then there is a rebuttable presumption of abandonment of continuous residence for naturalization purposes. The alien would have to show that he or she did not intend to abandon their permanent residence and that there were valid reasons for their extended periods outside of the US. If the absence is six months or less, then there is no presumption of a break in the continuous residence requirement.
Also, the applicant must reside within the state or within the immigration district where the application will be filed for at least three months immediately preceding the filing of the application.
In addition to the residence requirements, the applicant must also be a person of good moral character during the statutory period (3 or 5 years), and it must continue from the time of filing the application through the swearing-in ceremony. The term "good moral character" is not specifically defined in the Immigration Act; however, the courts have interpreted it to mean behavior that measure up to the standards of the average members of the community. The Immigration Act, in section 101(f), does list certain offenses that would preclude an applicant from establishing good moral character. These would include such crimes as murder, aggravated felonies (which are more fully described in the section under deportation grounds), certain gambling and drunk-driving offenses, prostitution offenses, etc. An applicant may also be found not to be a person of good moral character if he or she willfully failed to support dependents, committed adultery that destroyed a viable marriage, or willfully and knowingly failed to register with the Selective Service, if required to do so.

A person may take a modified oath provided his or her reason for doing so is due to deeply held religious or moral beliefs, which limit his or her willingness to bear arms and/or perform noncombatant services in the US armed forces.
Certain classes of persons are barred from naturalization. These include subversives; deserters from the US armed forces; those with a pending or final order of deportation (an exception exists for those who served honorably in the US armed forces for a period of three years or during times of war); and aliens who applied for and received an exemption or discharge from training or service in the US armed forces.
Applicants for naturalization must also be able to read, write, and speak the English language. Persons who are physically unable to comply due to a permanent physical or developmental disability, or permanent mental impairment are exempt from the literacy requirements. In addition, applicants who are more than 50 years of age and have been permanent residents of the United States for more than 20 years, or are more than 55 years of age and have been permanent residents of the United States for more than 15 years, as of the date of filing the application, may be examined in their native language rather than English.

All applicants are required to pass an oral test on the history and government of the United States. From a standardized list of approximately one hundred (100) questions, ten (10) questions are asked, and the applicant must answer at least six (6) correctly. (The complete list of questions and answers is provided on our web site). Aliens who are physically unable to comply do not have to take the test, and applicants over the age of 65 who have been permanent residents of the United States for more than 20 years are given a much shorter list of questions and answers to study. (Once again, these are included on our web site).