Whether he has to file a tax return depends on his filing status, age, and gross
income. Assuming he is a U.S. citizen or resident alien, and he is not blind,
he must file a return if he can be claimed as a dependent on another person's
return, he had any unearned income, and his total income was more than $1,250.
Examples of unearned income are taxable interest, dividends, capital gains,
and trust distributions. A dependent with earned income must file a return only
if his or her gross income is more than his or her standard deduction amount.