you can use this IRS website to check. Carefully read the questions.
https://www.irs.gov/help/ita/what-is-my-filing-status
but as @Bsch4477 pointed out you have to live apart for the last 6 months of 2023. if not, your choices are a joint return or married filing separately. As for who can claim your son if MFS either you both agree to who claims him or under IRS rules if you can't agree and he lived with both of you for the same amount of time during 2023 then the one with the highest adjusted gross income gets to claim him. also realize than MFS will like cost more in taxes than a joint return because certain credits and deduction are eliminated or limited when MFS.
