Added Later: One of my fellow interlocutors commented on my post:
The abundant misuse of apostrophes is mind-boggling.
According to a popular treatise on English writing, “The Elements of Style” by Strunk & White, which is commonly used as a textbook in college English courses, it is acceptable to use “‘s” after a name ending in “s”. Thus:
The Wilsons’ poodle got loose again
–is as grammatically acceptable as–
The Wilsons’s poodle got loose again.
(according to Strunk & White). i think the logic behind it is that it may help in understanding the meaning while speaking the sentence out loud to say “the wilsonses poodle”. purely speculation, though.
you may also often come across people who misuse apostrophes to denote the plural of something. “i saw there were many helicopter’s and plane’s at the airshow today.”
and don’t let’s get started on quotation marks…
I replied thusly:
Thanks a lot for bringing into my attention: (1) It’s very much acceptable to use (‘s) even after the words which end in ‘s’. Now, I remember that I had read that rule and I think it said that if you do use it, it’s not wrong, but somehow ( possibly because of redundancy in my mind) I made an impression in my mind that it should not be used.[Why use ‘s’ if you can do without it!]
(2) People do confuse in cases like “i saw there were many helicopter’s and plane’s at the airshow today.” I encounter such sentences every now and then.