How many times have you read a message like this:

“I could of jumped higher if I had the right shoes on."

Maybe you've penned a similar phrase, or maybe you're the type to cringe when you see it in writing. A lot of native English speakers get this phrase wrong, but let’s take a look at what happens and how to fix it.

First thing's first

When people say "could of" the phrase they're actually looking for is the contracted form of "could have" or "could’ve." When you say it out loud, though, it sounds almost identical, doesn’t it? It’s not that people won’t understand you if you say “could of.” The problem is, the spelling doesn’t make grammatical sense.

If you break the contraction apart, you get two separate words — could and have. Could have is a helping verb phrase in the conditional past tense, expressing possibility or necessity, also known as a modal verb phrase.

Should have and would have are other examples of conditional past tense phrases (that also fall victim to the same grammatical error as could’ve).

Meanwhile, “of” is a preposition. It creates a relationship, while “have” shows ownership. With that in mind, using “of” with “could” doesn’t work. Could isn’t forming a relationship with anything, but it does possess potential.

Can you still use could of?

You can, but that doesn’t mean you should. To everyone’s surprise, “could of” has been added to multiple dictionaries, with a caveat denoting it as a colloquial term. It’s used a lot, and it doesn’t matter that it’s used mistakenly. For hundreds of years, people have written “could of,” so it had to be acknowledged at some point.

Maybe you’re thinking, “Well, it’s in the dictionary, so it must be right!” You could take that stance, but that doesn’t change the fact that it’s a grammatical error. It’s just a grammatical error that made it into the dictionary by sheer popularity. Even the Merriam-Webster Dictionary of English Usage warns, “you had better avoid it in your own writing.”

No matter what the dictionary says, grammar rules still say there’s a right way to do things. If you’re just talking to friends, it might not be a big deal — they’ll know what you mean. Not to mention, the pronunciation distinction is barely there. If you’re writing articles, academic papers, a novel, or anything else you’re planning to show the world, you’ll want to get it right.

Then again, even if you don’t, you won’t be the first person to get something published using could of. Langston Hughes and James Baldwin both published works with the wrong phrasing, and both of their works survive today!