How to file 2009 income tax?

It is difficult to respond to your question as there are so many possibilities for which we do not have the required information to advise you. If he were a full time student and claimed as a dependent on his parents return he would not have been required to file a return if he did not have more than $5,700 income for any given year. Now if you were married in 2009 it is likely that you should file a joint return for that year. You will need to determine what his income was for the year. *