Did that headline stop you? Of course grammar is full of rules, isn’t it? Your seventh-grade English teacher tried her best to drum all those rules into your head. You remember all that red ink on your brilliant essays.

Hate to burst your bubble, but there is no set of definitive grammar rules. When Moses lugged those tablets back down the mountain, he didn’t carry a copy of the Chicago Manual or the AP Stylebook with him. I wish that had been the case, because it would have been a lot easier on those of us who write for a living.

You see, grammar is made up of a very fluid set of standards that vary by organization and occasion. Even the Chicago Manual and the AP Stylebook don’t always agree about key points.  Unfortunately, that doesn’t stop people from insisting that I don’t know what I’m doing because I did something that wasn’t in agreement with their favorite guide.

The simple fact is that every organization and decision-maker within those organizations has a preferred style. But there’s a big difference between preferred styles and hard-and-fast rules. For example, I’ve come to recognize that about half of people insist that the serial (or “Harvard”) comma always be used in a series of items. It’s the comma that comes before the “and” or the “or,” as in “He bought bananas, apples, and oranges.”

The other half believes that the serial comma is an abomination, and its use demonstrates that the user is sadly ignorant. So if you ask me to write a sentence with a series of objects, I’m either going to be 100 percent accurate in your eyes or an incoherent dolt, depending upon your stance and which English teacher terrified you the most.

Further complicating the matter, some companies have even developed their own style guides, and expect anyone performing work on their behalf to conform. As an example, I used to do a lot of writing for Amoco Oil, and anytime I referred to the fuel sold at their stations, I had to refer to it as “gasoline.” The shortened word most of us use, gas, was unacceptable.

So the next time you’re ready to dig in and insist that a particular rule is part of some inviolable code of grammar, stop. There’s no such thing. There are just styles and preferences. And if you expect a writer to obey yours, you’d be wise to share them before work begins.