There’s an annoying construction in English usage that I often see: the use of based off (or off of ) instead of based on.
It’s one of those incorrect, conversational English phrases that are growing in popularity and carrying over into writing. (It’s similar to the troublesome grammatical errors discussed in this post and this post.)
The noun base means something that serves as a foundation for something else. You put something on a base. The verb base means to form or serve as a base for.
Here’s an example of the correct and incorrect use of based :
Correct: The movie is based on the book.
Incorrect: The movie is based off the book. (This is also incorrect: The movie is based off of the book.)
The book is the foundation on which the movie is set. The movie is based on the book not off it or off of it.
Sometimes things might come off their base. But they don’t base off of their base.
(And don’t try to base something around something either. A base is at the bottom; therefore, you can’t base something around something else.)
Based on and based off are not interchangeable. Apparently the use of based off is rising (this likely has something to do with the Internet and the increasing use and acceptance of informal communication), but this doesn’t mean that based off is becoming correct.
So if people tell you based off is correct, tell them their claim is baseless.
If you pick up nonstandard English phrases through conversation or reading social media posts, go ahead and use them in speech if you want to. Informality is okay when you’re speaking; after all, you’re there, and you can clear up any confusion that a listener may have. But avoid these phrases in writing. If your readers think your literacy skills are questionable, they’ll question whether your text is worth reading.
There’s nothing wrong with using an informal tone in your writing, but this can be achieved with correct English usage. When you’re creating content (especially educational materials) for an audience that might include people who are not familiar with the nuances of conversational English, it’s best to stick with what’s correct.
