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.
The Hope for Children Act taking effect on January 1, 2002 provides an adoption tax credit of $10,000 for all adoptions from 2002 and thereafter, and a tax exclusion of up to $10,000 for employer-provided adoption benefits, effective in 2003.