Oldnproud
Whats the big deal with apostrophe's? 😁
The real purpose of an apostrophe historically is to mark a place in a word where one or more letters have been deliberately missed out. The patriotic song "Scots wha ha'e wi' Wallace bled . ." has letters left out from the words "have and "with".
Medieval lawyer's Latin was peppered with abbreviations using the things, as anyone is aware who has tried to work out for their family tree what an ancestor's will from the Tudor or Jacobean era is all about, and the original Domesday Book uses them a lot - for instance "p'sh" is the scribes shorthand for parish.
They are still in words that show possession - "Gilbert's house" would originally have been something like "Gilbertis house". Used correctly the should not be used in, say "The houses were painted white", because the sentence is not about something belonging to the house, but about the plural of house - one house, more houses. The possessive form would have once had more letters, but the plain plural would not.
"Don't" is an abbreviation of "do not", similarly with words like couldn't and didn't - letters left out and the gaps marked with apostrophes.
"Its" and "it's" seem as though they don't follow the rule, but one of them does.. "It's" has lost a letter from "it is", so it has the apostrophe to replace it, but in this case the possessive "its" doesn't have the apostrophe. There is always one that wants to be awkward!