My grandparent paid my tuition ($10,000) and I was a full time student for 2018 (age 22). W2 Income was only $3500, but I'm filing single and not a dependent on my parents return (did the same in 2017, though did not claim the credit). I don't know if I can claim the refundable part if someone paid that tuition as my income was so low (i.e. does this mean I do not cover half my support). Any ideas?
Not sure why you are not filing as a dependent because it certainly sounds like you are someone's dependent whether it be parents or your grandparent. You definitely did not earn over half your support if you have $3,500 in W-2 income.