Final answer:
The taxpayer's filing status depends on specific criteria, but with the death of the dependent child this year, they may no longer qualify as a qualifying widower, leading to a likely filing status of single or married filing separately if remarried.
Step-by-step explanation:
The filing status for a taxpayer whose spouse died in 2020 and whose dependent child died in the current year would depend on several factors. For two tax years following the year the spouse died, the taxpayer may be able to file as a qualifying widower if they have a dependent child. However, since the dependent child died in the current year, the taxpayer would generally no longer qualify for this status unless the death occurred on the last day of the tax year. If the taxpayer has no other dependents, then the taxpayer would likely file as single or married filing separately if they remarried during the year.