My grandson is 28 and had a stroke in 2012, prior to his stroke he earned $4790. He did not work anymore in 2012, can I claim him as a dependent for 2012?

Unfortunately, he earned MORE than the Gross Income Test, so for 2012, he will have to file on his own tax return.

For 2013 and beyond, you can claim him as a dependent if you provide more than half of his total support.