I would like to be enlightened on a question of grammar concerning the apostrophe.
I understand fully when one needs to be inserted when one talks about something belonging to the noun or pronoun.
For example: Les is going to Paul's house today
This is where the apostophe is placed correctly between the 'l' and the 's' at the end of Paul's.
However, I tend to get confused when it reads the other way round because I have seen examples of both the following and don't know which is the grammatically correct version or are both correct.
Example 1 - Paul is going to Les's house today
Example 2 - Paul is going to Les' house today
It seems that when the pronoun finishes with 'S' as in 'Les' sometimes an extra 'S' is added after the apostrophe and sometimes it's omitted.
Are both correct or is one wrong, or is there a qualifying situation for each to be correct in their own right.