My Google account

[Android Central Question]

I'm using a Galaxy A5 Duos that my mom used. I changed the Google account on the phone and for a while it was totally okay. But recently I have been unable to download or update any app due to an account error. When I clicked on 'Update' in any app, the Play Store screen popped up with this note 'Authentication is required. You need to sign into your Google Account.', while I was still logged in with my account. My mom had forgotten the account she signed the phone up with.

Please help. Thanks in advance!

 

[Velenoso]

Go to settings > google > google account will have user name and email, you might need your password from though.