U.S. National Proofreading Day is celebrated annually on March 8th. This day is dedicated to promoting and encouraging error-free writing. The aim of this day is to raise awareness about the importance of proofreading and to encourage everyone to take the time to ensure that their writing is free of spelling and grammar errors.

Judy Beaver, a corporate trainer, created National Proofreading Day in honour of her mother Flo. She loved to correct people. Here in the UK, it’s Mother’s Day in a couple of weeks, so we’re a big fan of this as a Mother’s Day gift for grammar nerd mums. 

On this very special day, we’ll cover a historical and very unfortunate proofreading error, as well as some common grammar fixes. 

The worst proofreading error of all time

Perhaps the most unfortunate error of all time is an error in the 1631 reprint of the Bible. It’s now known as “The Sinner’s Bible” or “The Wicked Bible.” Here’s why…

The word “not” is missing in the sentence “Thou shalt ___ commit adultery.”  


While it may have been a cause for celebration among adulterers at the time, the mistake was actually an error made by the Royal Printers in London, Robert Barker and Martin Lucas, who were reprinting the King James Bible first released in 1611. Although the circumstances remain inconclusive, some theorise it was an act of sabotage by a competitor. If so, that’s not very Christian of them.

The error was not discovered for a full year. By then, it was far too late. One thousand copies had been printed and circulated before the mistake was revealed by Dr. William Laud, the Bishop of London, who brought it to the King’s attention.

King Charles I was absolutely furious and demanded a good old fashioned seizing and burning. Of the books, not the printers. But he didn’t stop there where the printers were concerned. He also fired Barker and Lucas and fined them £3,000 (and, remember, this is the 1600s). 

The Archbishop of Canterbury, George Abbot, was similarly outraged, remarking:

“I knew the tyme when great care was had about printing, the Bibles especially, good compositors and the best correctors were gotten being grave and learned men, the paper and the letter rare, and faire every way of the beste, but now the paper is nought, the composers boyes, and the correctors unlearned.”

The Crown was, forgive the expression, hell-bent on getting rid of any evidence of this print run. But you know when celebrities delete a tweet that people have screenshotted already? Same issue, different technology. At least nine copies of the Sinner’s Bible are known to exist today. One copy sold in 2008 for nearly $90,000 in an auction.

And that concludes our cautionary tale. 

Actionable grammar tips

Proofreading is an important step in the writing process. It can help to improve the quality of your work and ensure that your message is conveyed clearly and effectively.

Proofreading the spelling and grammar of your writing keeps it polished and professional. Using a spelling and grammar checker, like the one built into Readable, makes this process a breeze. 

If you’d rather get it right the first time more often, a good practice is to look at the most common grammar trip-ups so you can write with confidence.

1 | Using homophones 

Homophones are words that have the same pronunciation but different meanings and spellings. For example, "there" and "their", "too" and "to", and "your" and "you're".

Check out our blog post on there, their and they’re.

Using the correct spelling with these types of words is one of the best ways to show attention to detail. 

2 | Using apostrophes 

Apostrophes are used to indicate possession or contraction. The most common mistake is using an apostrophe to make a word plural, for example, "apple's" instead of "apples".

If you can remember one rule about apostrophes, it’s this: possession, not plural. A bit of alliteration makes it easy to remember and it will really make a difference to your writing quality. 

3 | It’s vs its

Confusing "it's" and "its" - "It's" is a contraction of "it is" or "it has", while "its" is a possessive pronoun, “the dog ate its food”. Many people mistakenly use "it's" when they really mean "its".

It’s(!) very common, so if you don’t always pick it up, don’t worry - Readable has your back.

4 | Using commas

 Commas are used to separate items in a list, to separate clauses in a sentence, and to indicate pauses in speech. Misplacing commas can change the meaning of a sentence, for example, "Man, bacon makes everything better" vs "Man bacon makes everything better”.

To put more pleasant images in your reader’s mind, make sure your commas are up to scratch. 

By taking the time to proofread your writing, you can avoid making these common errors and ensure that your work is pristine. So, on National Proofreading Day, put it through Readable to make sure it’s ready to go.

Dave Child

Dave is the founder of Readable and has been building websites since the early 90s. He’s one of those fortunate people who gets to do what he loves for a living.