Spouses are not counted as dependents on tax returns. Filing jointly does not require that you both have income. You can file jointly, and then both of you are included in the calculation of the standard deduction. If you file separately, then you each have a standard deduction for that filing status.
Generally, filing jointly will give you a bigger refund or less taxes due. When you file separately, your tax rate is higher and you won't be eligible to claim certain deductions or credits that are only available on a jointly filed return. Therefore, even if your spouse did not have any income, it may be more beneficial for you to file jointly.
Here is more information on whether to file jointly or separately:
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