Iíd like to ask you about the possessive form of a proper noun which ends with ďsĒ.
Should it be Nickolasís or Nickolasí?
If it is Nickolasís, how should it be pronounced?
It is pronouced 'nickolases'. Traditionally Nickolas' has been the most accepted form but nowadays both are used, and there is some debate over which is correct, so, as far as I'm concerned they are both OK. I tend to lean towards Nickolas's as that is how it is pronounced.