My partner and I have lived together for the past 8 years. The last 4 years have been in georgia. Can this be a common law marriage?

Georgia does not recognize common law marriages.

So if you are not legally married you each will have to file your tax returns as Single.

Georgia does not recognize common law marriage.  She may be your dependent IF she had less than $4200 of income in 2019, not counting Social Security.

 

You might get the $500 credit for other dependents:

CREDIT FOR OTHER DEPENDENTS

https://ttlc.intuit.com/questions/4499708-what-is-the-500-credit-for-other-dependents-family-tax-credit

 

If you were legally married, your tax picture would be different.