In general, an apostrophe before the “s” indicates a singular possessing something, while an apostrophe after an “s” indicates the plural possessing something—e.g. “the soldier’s guns” vs. “the soldiers’ guns.” Contractions are another use, and the contraction “it is” tends to cause many mistakes because it involves an “s”.
hmmmmm, then the below is correct usage? I am certainly no expert on grammar, lol. And I avoid contractions as much as I can since I was taught (again back in grade school) that contractions were for lazy writers. I expect things to heat up if I understood you correctly and the below is correct usage. I look forward to getting a lesson on English grammar.
the world’s richest city