Quote Originally Posted by Arcon View Post
It's not wrong to add an extra "s", and it is in fact often encouraged. It's been suggested quite often to always use the extra "s", and reserve the s'-ending for plural nouns or special exceptions, like traditional names (Jesus' Ukonvasara or something like that).
This is totally correct. When a word ends with "s", using either "'s" or "'" is acceptable. I've also always preferred "'s" because it makes the singular nature of the word clear, and I have a horrifying protuberance for clarity in language. I didn't know the bit about traditional names, so that's informative for me.

Although, I think Jesus would prefer a Yagrush instead. It's more useful for curing blindness AND carpentry work.God would use a Tupsimati because he apparently enjoys making awful things and the suffering that follows.