I have some questions about filing a 1040 tax return. If the husband's wife died on June 6, 2019, then he files for 2021 Federal Tax Return in 2022. Is the husband required to file as a qualify widower or MFJ? If he qualifies for qualify widower, does he have write down the wife name and SSN on 1040 form in the joint return box?
If his wife died in 2019, and he has not remarried, he cannot file as married filing jointly (MFJ) for 2021 because he was not married in 2021. He can file as Qualifying widow(er) for 2021 if he meets all the requirements. He does not enter his deceased wife's name or Social Security number.
If the wife died in 2019, he can file as married filing jointly in 2019 but not in 2020 or 2021. He could file as qualifying widower in 2020 and 2021 if he meets the requirements for qualifying widower filing status. That status is only allowed for 2 years after the year of death of the spouse.
If the spouse died in 2019 the surviving spouse can file as QW for 2020 and 2021 only but only if not remarried and if they have a dependent child who lived with them the entire year and paid more than half the cost of the household. You do not check the box for a joint return. There is a separate box for QW.
2019: File MFJ
2020: FIle Single (assuming not remarried and has no children thay may qualify you for QSS - Qualified Surviving Spouse status)
2021: Same as 2020
2022: File single (assuming not remarried)
you can test your scenario at the IRS website:
https://www.irs.gov/help/ita/what-is-my-filing-status