(1) five years continuous residence (three years if married to a US citizen), of which at least half the time must be spent physically in the United States;
(2) residence of 90 days in a particular USCIS District prior to filing;
(3) ability to read, write, and speak English;
(4) knowledge and understanding of U.S. history and government;
(5) good moral character; and
(6) support for the principles of the U.S. Constitution.
The continuous residence, physical presence and good moral character requirements are the most common pitfalls for applicants. If you are interested in applying for naturalization, I invite you to contact me so that we can assess your eligibility.