Why is "would of" a mistake?

Would of, could of, and should of are mistakes. Have you ever found yourself writing any of those?

Writing of in those cases is a dead giveaway that you don't know grammar...but don't fear! This lesson will help you understand why of is wrong and why you should use have or 've instead. Here we go!

It makes sense that people make this mistake because of and have sound so similar when we say them out loud. This is especially true when we use the contractions would've, could've, and should've.

But don't get tricked! Have (or 've) is the correct choice.

Incorrect --> Correct

I would of called you, but I lost your number. --> I would've called you, but I lost your number.

I could of danced all night. --> I could've danced all night.

I should of ordered a salad.- -> I should've ordered a salad.

Would, could, and should are helping verbs that need to be a part of something called a verb phrase. Verb phrases are made up of one ore more helping verb and a main verb.

Have can function as a helping verb. Of can't. 

In our incorrect sentences, would, could, and should are followed by the word of, which is hopelessly trying to be a helping verb. But no matter how hard it tries, of is limited by its definition and function.

Of is a preposition. Its job is to show how nouns relate to the rest of a sentence. 

The word that people mean to use here is the verb have. 

Have, or the contracted version 've, is a verb. That means that it's happy to function as a helping verb along with would in order to create a verb phrase. 

The verb phrases in our example sentences are would have called, could have danced, and should have ordered.

Would, could, should, and have are helping verbs. Called, danced, and ordered are main verbs.

If you want to learn more about how words like of and have work, our Get Smart Grammar Program will teach you. Watch the short instructional videos, diagram sentences, and enjoy learning how our language works. I'll make it really easy on you! I promise. 

Does the would of issue make sense now? Here's what we covered on this page: 

• Would of is a mistake. 
• People make this mistake because when we speak, the contraction would've (a contraction for the words would have) sounds like would of. 
• Would have or would've is correct. 
• Would and have are helping verbs. They help create a verb phrase. 
• Of is a preposition and not a verb, so it can't be a part of a verb phrase. 

If you'd like to teach or learn grammar the easy way—with sentence diagrams—check out our Get Smart Grammar Program.

It starts from the very beginning and teaches you grammar and sentence diagramming in easy, bite-size lessons.