This is most likely to happen on a normal GUI system like Ubuntu or Linux Mint. If you or the user is meant to have sudo / root privileges it is as simple as editing the following files:
Now assume your username is "iamtheuser"
vi /etc/group
adm:x:4:syslog,iamtheuser
sudo:x:27:anotheruser,iamtheuser
Find the above lines and add a comma and "ia........