Is this person a Resident Alien or Nonresident Alien?

As itonewbie pointed out, you will need to ask about the details about how long this person has been in the US, as well as look into the rules of "exempt" days for a "J" visa (check out Publication 519).

If this person is a Nonresident Alien, are you thoroughly knowledgeable about Nonresident Alien tax returns?  If not, you may consider passing this one to a more experienced person.  Preparing a tax return for a Nonresident Alien is an entirely different specialized field, and unless you have done extensive research on the matter, in my opinion most tax professionals (including myself) should NOT be preparing returns for a Nonresident Alien.