Misuse of apostrophes is the classic mistakes which picky grammarians use to fuel their campaign about the importance of correct punctuation.

Of course, the two instances in which the apostrophe is commonly used are to indicate missing letters in an abbreviation (eg don’t, won’t, can’t, shouldn’t, that’s) and to indicate possession – something belonging to someone or being a quality of a particular person or thing (eg the boy’s shoes, the woman’s car, the dog’s friendliness, the flower’s beauty).