You figure differently from the way the tax law figures. Your filing status is determined by your marital status on December 31, no matter how long you were married. Since you were married on December 31, your only choices for filing status are married filing jointly or married filing separately.
The status that you indicated on the W-4 form that you gave your employer, which may be shown on a statement attached to your W-2, does not affect the filing status on your tax return.
