If your spouse sponsored you and you are still married, you may apply for your citizenship 3 years after receiving your green card. However, you must still be married and living with your sponsoring spouse. Furthermore, you will need your spouse’s cooperation and provide proof that you and your spouse are still married and living together. Among the proof you will need are joint tax returns and a lease or deed that shows the marital residence is in both names.
If you can’t meet these requirements you may apply for your citizenship on your own after 4 years and 9 months after receiving your green card. If it has been 4 years and 9 months since you have received your green card you will not need to still be married to your sponsoring spouse.