Lime Time Fitness is no mom-and-pop outfit. It sports nearly 200 locations sprinkled across the US, with plans for expansion. Monthly dues aren’t cheap, but I take my fitness seriously and get my money’s worth. I can justify its monthly cost. Normatecs don’t suck.

While stretching the other day, I noticed the following sign on the floor—and something seemed off. See if you notice the error.

Give up?

A workout is a noun. As a verb, though, work out is correct. The sign should read: How Hard Should I Work Out? (Grammar Girl would be proud of me.)

What You Need to Know

Everyone makes mistakes from time to time, even yours truly and a well-resourced corporation with its own marketing and communications department. The latter prints a grammatical error on presumably hundreds of signs (in the title, no less). Given that, what are the odds that you’ll be able to accurately edit an entire book by yourself?

Sadly, plenty of authors eschew proper editors in favor of doing the job themelves.

I’ll give you a hint: The answer starts with a z.

I swear by Grammarly as I write my manuscripts, but it’s certainly not perfect. No tool is. What’s more, it doesn’t work in galleys. I’d never dream of publishing a book or any long-form content without hiring a proper editor—and neither should you. (Thankfully, Racket works with some amazing ones.)

Sadly, however, plenty of authors eschew proper editors in favor of doing the job themselves.

Without any further information, which category of books contains more typos, grammatical errors, and other linguistic gaffes?