Hi There,
I was a student here in US till the end of Dec and graduated in Dec 2007. Let me break down my points for easy reference.
1. I was on OPT from Jan 2007 to Jan 2008 and hence was working fulltime.
2. Within the same time, that is from Jan 2007 to Dec 2007 apart from working I was also taking courses and paying the school tution(I have received a 1098-T from my school for this).
3. Also my employer in error deducted Social Security and Medicare taxes in error for 2 months.
4. I bought a new car within the last year(can I claim sales tax?).

I would like to know what are the tax return forms I need to fill for last year.

Thanks,
Rakesh

Rakesh:

Assuming you arrived in the U.S. AFTER 31 December 2002, you will file as a non-resident alien for 2007, filing either Form 1040NR or 1040NR-EZ. If you arrived PRIOR to 1 January 2003, let me know the details, for the rules are different for you.

For Item #3, ask the employer for a refund of the taxes withheld in error. If they refuse, get the refusal IN WRITING. You will need the written refusal when you file Form 843 (separate from your tax return) to request the refund from the IRS. See IRS Pub 519, page 48.

For Item #4, No.