If you are at least 18 years old, you must be physically present in the U.S. for at least 3 months before you can apply.
Other requirements are the following.
Live in the U.S. for at least five years as a PR (or three years if married to and living with a U.S.citizen).
Are present in the U.S. for at least 30 months out of the past five years (or 18 months out of the past three years if married to and living with a U.S. citizen).
You are a good moral character.
No any crime against a person with intent to harm.
No any crime against property or the government involving fraud.
...
At last, pass English and civics tests.
