I’m single with "a dependent ".
You don't say how the dependent is related to you. An unrelated dependent cannot be claimed for the (up to) $2000 child tax credit; but my still qualify for the $500 other dependent credit. A common example: you cannot claim your live in girl/boy friend's child for the child tax credit
There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, student status, a CLOSE relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit and the Child Tax Credit. They are interrelated but the rules are different for each.
See full rules at: https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...
