Just always make sure to put an alias to any column you are customizing/formatting. It's like this:

SELECT ID,

FName+' '+MNane+' 'LName FullName, --on this Line, Name is the Alias

ISNULL(Address, 'TBD') FullAddress, --on this Line, FullAddress is the Alias

Occupation,

Month(Birthday) BirthMonth --on this Line, it is the BirthMonth

FROM TBL_PeronalInfo

Hope I explained it clearly...