“I had no earned income, but I had scholarships and grants of $6170. My roommate has paid all of the bills. Can he claim me?”---->It depends on; as long as the whole amount of your scholarships and grants are treated as your taxable income, then your room mate CAN’T claim you as his/her dependent even though he/she provides you over half of your support; your gross income can’t be above the exemption amount, $3,650 in 2010.
“ Do I need to file a return?”--->It depends; your scholarship may count as income; if so, it will be taxed .For instance, if your sccholarship is used to cover: Room and board, Travel, Research, Clerical help, and Equipment. However, remember. If your award, for example, covers both tuition and room and board, the amount you use for tuition is tax-free, while the amount you use for room and board is taxable. Your grant is a scholarship or fellowship and is to be used for study at an educational institution that normally maintains a regular faculty and curriculum and normally has a regularly organized body of students in attendance at the place where the educational activities are carried on; grants to individuals for travel, study, or other similar purposes (including loans made for charitable purposes, and program-related investments) are taxable expenditures, unless the following conditions are met: your grant must be awarded on an objective and nondiscriminatory basis under a procedure approved in advance by the Service, and It must be shown to the satisfaction of certain Service. Though your scholarships and grants of $6,170 is counted as taxable income, you, I assume you are single, do not need to file your return; as your gross income, $6.170, is less than $9,350;$3,650+$5,700=$9,350.