If you’ve been in the writing and publishing world for even five minutes, you’ll probably have heard the one complaint that unites editors and grammar geeks everywhere, in a red cloud of linguistic and punctuational rage: nobody seems to know when to add an apostrophe to “Its!” For sign makers, “It’s” with the apostrophe appears to be ubiquitous (and is almost always used incorrectly), and even seasoned writers seem to be vague about when to use the apostrophe and when not to.
But if this is something you’re unsure of, I will tell you a secret now that will change your writing life forever: it is extremely easy to know which form to use. Believe me about that. It is easier than you have ever imagined.
Take this sentence:
“The snowball hit the car on it’s windshield.”
Now apply this simple, easy rule: If you can substitute “it is” (or “it has”) in place of “it’s,” then you can use the apostrophe.
That’s the only rule you ever need to know, to tell whether you should write “its” or “it’s.” So let’s apply it to our sentence:
“The snowball hit the car on it is/it has windshield.”
Um…no? That sounds awful, and is clearly incorrect. So you don’t need the apostrophe there. Use “its” instead of “it’s.”
And this sentence?
“Its a bright, sunny day.”
Applying our substitution rule:
“It is a bright, sunny day.”
And this means that yes, you do use the apostrophe. So be sure to stick it in.
Let’s repeat the rule: If you can substitute “it is” (or “it has”) in place of “it’s,” then you can use the apostrophe.
Isn’t that easy? That’s the only rule you will ever need to know, to decide whether to use “its” or “it’s.” Because the only time you ever use the apostrophe is when you really mean “it is.” Knowing that, you should never make an error with that word again. Simple!
(Thanks so much to Christopher for pointing out that you can use “it has” as well as “it is.” I’ve added that set of words into the rule too. Picture me slapping my forehead. 🙂 )
(And by the way, if you’re vague about the apostrophe in general, and would like a little guide on how and when to use it, you can download my free PDF, That Darned Apostrophe! It covers contractions, possessives, and plurals as well as the its/it’s confusion.)