Dual Status Tax Return :           Generally you will be considered as Dual-status resident in the year you arrive in or depart from US. You can be both a non-resident alien and a resident alien during the same tax year.     Different rules apply for the part of the year you are a resident and the part of a year you are a nonresident, in determining your US income tax liability for a dual-status tax year.           For the year in which you arrive in US , you can make the First year choice and to make this choice you must :           1] Be present in US for at least 31 days in a row in 2008 2] Be present in US for at least 75% of the number of days beginning with the first day of the 31-day period and ending with the last day of 2008 and 3] That you are a resident under the substantial presence test in 2009       If you make the first year choice, your residency starting date for 2007 is the first day of the 31-day period that you use to qualify for the choice. You are treated as US resident for the rest of the year.       You must attach a statement to Form 1040 to make the first-year choice.       The benefit of claiming First-year choice is you may be eligible to claim exemption for your spouse and dependents and also eligible to claim certain tax credits.           Last year in which you depart from US it is considered as Last Year of your US Residency and the residency termination date will be the last day you are physically present in the United States in that year. It is mandatory that you file a Dual status return and there is no choice as you have in first year as explained above.           Residency start and termination dates determine which income you need to report on your US tax return, for example, in case of Last year of residency you will not be taxed on all foreign source income and US source interest and capital gains income after your residency termination date.           In case of Dual status tax returns, you can not claim standard deduction.