Recognize an apostrophe when you see one.
Although the apostrophe might look like a comma defying gravity, this mark of punctuation has three distinct jobs: to show possession, make contractions, and form odd plurals.
Use the apostrophe to make words possessive.
You can show possession the long way or the short way. The long way requires a phrase using a word like belong or own. A preposition such as of will also do the trick.
The donut belonging to Vince
The hot sports car owned by Sylvia
The home of the Watsons
Showing possession with an apostrophe [and often an added s] simplifies the phrasing:
Sylvia’s hot sports car
The Watsons’ home