If you have obtained
green card with some condition on the residence, it is because of the reason; many fake marriage happens to get US citizenship benefits. So the immigration officials provide green card which on some residence condition of which he/she can't cheat US.
For example, an alien residence married to US Citizen, the alien will hold green card on condition for almost 2 years of which if both of them stick together paying taxes and marriage is genuine then alien who had green card on condition will be removed using the
Form I-751.
