When should you use an apostrophe?
More people overuse apostrophes than underuse them.
Often, I see apostrophes in words that are meant to be plural, but not possessive.
e.g. The photo’s look great.
It should say: The photos look great.
Sometimes people use apostrophes with pronouns.
e.g. her’s, it’s, our’s, their’s, who’s, your’s — these are all WRONG if you’re trying to show ownership. They should be written: hers, its, ours, theirs, whose, yours.
Be aware that apostrophes have two separate uses. One is for showing ownership, as in the cat’s whiskers. The other is to show that one or more letters have been taken out (contractions).
Some of the words can be confusing.
e.g. Let’s means let us, but if you meant to say that someone allows you do do something, it should be, “She lets me go to the movies.”
Who’s means who is, but if you meant to ask who owns something, you would say, “Whose dog it that?”
And the most troublesome of all … it’s or its.
It’s means it is, but if you are attaching ownership, you would say, “The dog should pay attention to its master.”
There was a time when the general rule was to use apostrophes to show possession for people and animals (the dog’s fur, the lady’s hat), but to use “of” for inanimate things (the hood of the jacket, the eye of the needle), but this is now being disregarded in many cases. It seems to me that it’s perfectly acceptable to refer to “the car’s windshield” or “book’s cover.”
One of the most common errors I see is the use of an apostrophe with decades.
e.g. The Beetles were popular in the 1960s. There should be NO apostrophe.
But if you shorten the decades to refer to the ’60s. This apostrophe is correct because it shows that something has been left out — in this case, the 19. Be sure that the apostrophe is turned to face the same direction as a comma (not as at the beginning of a quotation).
Placement: The apostrophe comes after the word that has the ownership. If it is a singular noun, then you would put the apostrophe after that noun. If it is a plural noun, then put the apostrophe after the end of that word.
e.g. This is the dog’s collar.
These are the dogs’ collars.
The use of apostrophes is more complex than one page can do justice to, but consider this a beginner’s list of basic helpful hints.