You can claim a
qualifying relative as a dependent if you answer "yes" to all the
following questions:
Are they a U.S.
Citizen, a U.S. national, a U.S. resident, or a resident of Canada or
Mexico?
You can't claim someone who
is married and files a joint return with their spouse, takes a personal
exemption for themselves, or claims another dependent on their own tax
form. Are you the only person claiming this dependent?
Did this person earn less
than $4,050 during the year you're trying to claim them as a dependent?
Did you provide more than half the cost of their living expenses for the
year?
Did they live with you all
year as a member of your household?
If you don't see
your situation here, a comprehensive list of rules on claiming a dependent is
available here.
You can also refer to IRS
Publication 501