Married but wife did not work 2020 tax year, how do I file married jointly or head of household? and do I add her as a dependent since she did not work. I was sole income

[shariroha]

You will need to file married jointly.  Being that you are still married at the end of 2020, your status to file is still married jointly even though she had no income (i.e. she is a stay at home mom).    Head of household only applies if you have dependents that you supply care to more than 6 months out of the year that are not your spouse and live with you.

[JoannaB2]

Married couples have the choices of filing separately or married filing joint (which allows the couple to file only one tax return, but both spouses are equally responsible for any taxes and penalties owe).  Even, if your spouse didn't have income, you can still file married joint, but your spouse can never be your dependent.  For federal income tax purposes, head of household is an unmarried taxpayer who has dependents and paid for more than half the costs of the home. The unmarried taxpayers can be a single parents, divorced, or legally separated parents (by the last day of the year)