I was student on F1 visa from year 2008 to 2010. I had no income on 2008 and 2009. After graduating in MAY 2010 , I got my OPT during June 2010 and worked for 2 months in USA and I had income during that 2 months. Now I am back in my country.
I did not file the Form 8843 for 2008 and 2009. Can I still file the Form 8843 for those 2 years? What should I file for the year 2010?

On F1/OPT you are exempt from residency for 5-years. For 2010 you must file non-resident tax return Form 1040NR or 1040NR-EZ and Form 8843. Your income is not subject to FICA taxes but you must pay federal and state income taxes. On your income you will get deduction based on tax treaty between the U.S. and your country.
For 2008 and 2009 you should file Form 8843.
Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents (http://taxipay.blogspot.com/2008/03/us-tax-filing-requirements-for-non.html)

Thanks for the help