Personal Exemption. You are generally allowed one exemption for yourself. If you are married, you may be allowed one exemption for your spouse. These are called personal exemptions.
Spouse Exemption. You can claim your spouse as an exemption if you file either (1) a joint return, or (2) a separate return and your spouse had no income and is not filing a return.
However, do not check the box for exemption if your spouse can be claimed as a dependent on another person's return. If you were divorced or legally separated at the end of last year, you cannot take an exemption for your former spouse. If, at the end of the year, your divorce was not final (an interlocutory decree), you are considered married for the whole year.
Death of Your Spouse. If your spouse died last year and you did not remarry by the end of last year, check the box if you could have taken an exemption for your spouse on the date of death.