Is it true that if someone is in the USA illegally for ten years, but has been paying taxes, that they can get a greencard?
Not really. It sounds like you are referring to something called “Cancellation of Removal”, which is a defense to a charge of being removeable. Once a person, who has been in the USA for at least ten years has been charged with being removeable, he or she can apply for Cancellation of Removal if: -He or she is a person of good moral character;and -His or her removal would cause exceptional and extremely unusual hardship to his or her citizen or permanent resident parent, spouse or child. Having filed tax returns is one way of showing good moral character. If all of the above is established in Immigration Court, the Immigration Judge can cancell his or her removal and adjust his or her status to lawful permanent resident. It should also be noted that under a law known as NACARA, certain perople from the former Soviet Union and some Central American countries be granted Suspension of Deportation under lower standards, or more easily.