You are not a citizen until you are sworn in. If you are denied because of failure to pass the English or the civics test, you will be automatically rescheduled within 90 days. If you are not approved for some other reason, you may be given time to overcome the problem.
For 2009, the American Opportunity Credit--which is a variation of the Hope Credit--will be allowed for 4 years. For years before and after the new credit is allowed, the Hope credit is supposed to be for 2 years.
Add the number of years of the statute of limitations in your state. For Example: You last stopped paying on a credit card on January 15, 2015. The company sent you a demand letter for the full amount on July 15, 2015. The statute of limitations for credit cards (usually regarded as open accounts) in your state is 6 years. The date at which you are safe from having a creditor sue you over this debt is: No Acceleration Clause: January 15, 2015 + 6 years = January 15, 2021