I like the greengrocers signs with apostrophes. I saw one where a potato owned some tomatoes, cucumbers and some eggs.
Potato's, tomatoes, cucumbers and eggs.
Elegran and duramjen - please don't stop using "so" at the beginning of a sentence, language is changing all the time it's just a personal thing with me. My sons use "so" all the time.
I used to teach the apostrophe and we had fun with Santa and his Grotto. i.e. Santas' Grotto. How many Santas how many Grottos. 
There is talk about stopping the use of the apostrophe. It is complicated and before I taught it I had to look it up and study it quite closely.