top of page

3 marketing copy myths busted: grammar rules for advertising

Updated: Nov 8, 2023

A complicated road sign in the desert - this explanation of how to write marketing copy will be simple
This is going to be nice and straightforward.

Grammar rules for advertising are a little different to your everyday language.

We're not exactly using incorrect grammar on purpose...

It's more that we're bending the rules slightly to create more of an impact.

Sometimes though, those “rules” we're bending aren't actually rules at all:

They're just things that various schools taught at one time or another for no particular reason.

Let's take a look at which are just straight-up examples of poor grammar...

And which are little tricks we can use to nudge our marketing copy in a more powerful direction.

Are grammar rules for advertising the same as you'd learn in the classroom?

Grammar rules for advertising are not the same as this kid is learning in the classroom
"Learn these rules now and then you can ignore them for the rest of your life."

No, they're not the same. Honestly, I don't really remember my secondary school grammar lessons. Kudos to you if you do!

These days, though, it's my job to learn about these things.

So, armed with little more than my determination to keep particularly pithy phrases I've written from being watered down by a bucketful of boring grammar rules, I trawl the internet and pick up honest-to-goodness grammar books...

All so you don't have to.

Here we go!

Straight-up examples of poor grammar

Some classroom rules were made to be broken. Others were not. I'm not trying to encourage you to write in terrible broken English here.

For instance, the kind of copy produced by those copywriting companies who have stables of writers churning out cheap SEO articles that are barely legible really gets my goat.

Who's benefiting from having copy like that anywhere near their brand?

But leaving those guys aside until after the revolution, there are still plenty of real world grammar mistakes that are easy enough to make.

When we're talking about “bending some rules”, these are not they:

1) Possessive apostrophes

Some school grammar rules need to be kept, unlike what this child is doing on this blackboard
"Crossing ma i's and dotting ma t's..."

This is a big one. It's probably the most common example of poor grammar you'll come across.

I see it on shop signs all over the place. I'm sure I'm not alone.

It often crops up when someone really wants the plural form of a word ending in “y”.

Victoria's Secret famously did this in massive font on a multi-million dollar advertising campaign.

Their slogan was:

You've never seen “body's” like this.”

Those quote marks in the middle aren't there for effect. That's really how they chose to highlight their probably deliberate yet massive mistake.

In fairness, the range they were advertising was called “Body by Victoria” so perhaps they were trying to do keep the name intact?

Whatever. It still looks terrible!

2) Its/ it's

This is probably linked to problema número uno, the possessive apostrophe. It's kind of reversed here:

  • “It's” is a contraction of “it is”

  • “Its” is the possessive

Don't mix them up.

3) Your/ you're AND they're/ there/ their

These are the sorts of school-taught rules we're not playing around with. Each of these has a place where it lives for very good reasons.

Don't make the mistake of using homophones like these or even similar-sounding words in place of each other.

If writing and grammar are not your thing, not to worry. Hire a professional copywriter to do it for you. It's pretty gosh darn affordable.

If you're doing it yourself and never feel 100% confident in your use of language, just be sure to check it multiple times using a grammar checker.

This is doubly important if it's going be on a sign or somewhere else very obvious like a title or advertising literature.

4) Could of vs. could have

Many people write or say “could of” or “should of” when they actually mean “could have” or “should have”.

I think this might come from accents or habits of pronunciation.

If you say “should've” or “could've” quickly, it sounds like they're contractions of “should of” or “could of” rather than the “have”s they actually are.

It's easy enough to do. It's also more than a teensy bit wrong.

5) Abbreviations

Some people drop “etc.” and “&” into their copy anywhere they possibly can.

Even in professional or customer-facing writing. Even when writing blog posts, web copy, and other long-form content where there are no space limitations at all.

Now, there's an argument for using ampersands anywhere there's a character count (such as meta titles and descriptions or some social media platforms).

I would say they're not really suitable for most marketing purposes though. They're a bit too casual. They make your writing look unfinished.

You should definitely never pair ampersands with an Oxford comma. Look at this:

McCartney, Lennon, Harrison, & Starr.”

Ugh. No. Write out the word “and” in full.

Or, if it's a brand name (law firms are commonly made up of the names of multiple partners like this), skip the final comma altogether.

6) Acronyms

Acronyms are usually simple. Introduce your first YOLO (You Only Live Once) use of an acronym in brackets like this. Then have at it from then on.

This is important even for abbreviations and acronyms that are common in your industry. Those bread-and-butter jargon terms you use every day.

I work with some clients in complex technical fields like app development and cybersecurity. Let me tell you, there are enough abbreviations to keep a ship afloat.

But don't assume your audience will automatically know what they mean. They might know as much as you. They might be reading your article because they don't.

7) Semicolons

Semicolons connect two independent though closely linked causes.

You should probably just avoid these in most advertising copy. There are a few places where they might be useful, but not many.

One of my first editors called them “a little highbrow” for most copy. I think he's right.

I occasionally also see them used to end bullet point lists. I find this a little bit incomprehensible.

It's already in a list format, guys. No need to separate it any further.

For lists, use a full stop if it's a sentence. Otherwise, there's no need to use anything.

Image of a list in a work setting demonstrating semicolon use in marketing (i.e. none)
Not present in this list? Semicolons. Admittedly, also currency symbols because we are so hipster.

How to write marketing copy – when a mistake isn't a mistake

So, some mistakes are outright errors.

But there are many grammar rules that either aren't rules at all or that we can kind of gloss over when writing marketing copy.

There are also some we can actively embrace the exact opposite of:

1) “You can't start a sentence with a conjunction” (Myth!)

This is a point I occasionally discuss with clients. It's easy enough to see why lots of people don't like seeing this done:

Dictionary definition-wise, a conjunction is a word that is used to connect clauses or sentences or to coordinate words in the same clause. Examples are:

  • And

  • But

  • If

  • Or

It follows, you might think, that if a conjunction connects clauses, it can't connect the first clause to nothing. Can it?

Well, that is very logical. It's also not at all true.

There's no rule that says you can't start a sentence with a conjunction. You'll see these “grammatical errors” in published books – both fiction and non-fiction – all the time.

I'll level with you:

I love starting the occasional sentence a conjunction. I think it can make any bit of writing more hard-hitting. I went through a brief phase of doing it everywhere.

But, as with most of life, all things in moderation.

(See what I did there?)

A wall carving of a myth - not a marketing copy grammar myth - but a myth all the same!
So many myths, so little time...

2) “You can't split an infinitive” (Myth!)

Yes. Yes, you can split an infinitive.

This rule was taught in English language classrooms across the UK, in particular, for many years. Yet there is no real-world grammar rule that says you can't do it.

I mean, the Victorians thought you absolutely should not split an infinitive. But they also thought smoking was good for you.

An infinitive is a form a verb can take. Technically, it's “a verbal that can function as noun, adjective, or adverb.” In the example below, the infinitive is “to go”.

Essentially, an infinitive is always “to” and a verb.

A split infinitive is when an adverb is placed between the “to” and the verb.

Check out this article in The Guardian where they mention one of my favourite, highly emotive science fiction quotes (I'm a geek; sue me) in relation to this:

To boldly go where no one has gone before.

See where ”boldly” has jumped in there? That infinitive is well and truly split. It's also creating much more of an impact than “to go boldly”.

(To the uninitiated, the line is from Gene Roddenberry's Star Trek. That's the one with no little boys with magic wands, fewer laser swords, and precisely zero Princess Leias.)

3) “The Oxford comma is/ isn't mandatory” (Myth!)

The Oxford comma debate – somehow – still rages on. I mean, I get it.

I used to be dead set against them. Nasty, unnecessary things cluttering up a perfectly good sentence.

Only, I don't think that any more. Now I use them most of the time.

Just to be clear, the Oxford comma is the last comma in a list in a sentence. Here's an example:

I like walking, running, and dancing.”

The Oxford comma is the one just after “running”. Sometimes you'll see it called the “serial comma”.

Most people who write more than a little (certainly people who provide SEO copywriting services for a living) have what we might call strong opinions about them.

Funny thing is though, using an Oxford comma isn't either grammatically correct or incorrect in British English. It's basically optional.

Whether you use one will likely come down to:

  • Personal preference

  • The type of writing it is

  • The style guide you're using

(The whole reason it's called the “Oxford” comma is that it's the official style of the famous Oxford University Press publishing house.)

However. It's not always as simple as “I always use the Oxford comma” versus “I hate the dang things. Keep them away from me.”

Why you SHOULD use the Oxford comma

There are many times when using the Oxford comma makes a sentence much clearer.

Take the classic, I would argue amusing, example (outright stolen from a brilliant greeting card I thoroughly encourage you to search for):

We invited the strippers, JFK and Stalin.”

Without a serial comma, we are potentially inviting two expert clothes removers named after historical world leaders to our party. Now consider this version:

We invited the strippers, JFK, and Stalin.”

With the Oxford comma, it's much more likely that the guest list includes an unknown group of strippers plus two named individuals.

Legal experts tend to be trained to use the serial comma. There have been actual multi-million dollar lawsuits because of ambiguity caused by a lack of an Oxford comma in a contract.

For many lists, this means including an Oxford comma is often more beneficial than not. It's not a set rule though...

Why you MIGHT NOT use the Oxford comma

Yep, there's another massive “but” coming this way.

In grammar, there is such a thing as an “appositive”. You'll recognise these even if you don't know the word. Consider this example:

My friend, Rob, enjoys the theatre.”

In this, “Rob” is the appositive. It's a noun phrase that comes immediately after another noun phrase (called the “antecedent” – in this example, “my friend”) that adds some detail to it.

The problem with using an Oxford comma by default is that it can introduce some confusion if there's a possibility it could actually be an appositional comma.

Let's take a look at the Oxford comma version of that first example again:

We invited the strippers, JFK, and Stalin.”

Now, what if those first two noun phrases were in apposition to each other?

I mean, they could be! A band of strippers called “JFK”? I've heard of weirder things.

This is an example of the Oxford comma not necessarily clearing things up. Maybe split your sentence in two or just rewrite it in this case.

BONUS! “One-word sentences and sentence fragments aren't a thing” (Myth!)

There are certain rules that describe what technically constitutes a sentence. For example, a sentence needs to have a subject and a verb.

I think, technically speaking, a paragraph also needs to have a minimum of three sentences...


Sorry if that objection was too technical. Let me rephrase:

Shorter sentences are, generally speaking, better.

If you want to check out some some fantastic marketing copy which exploits the power of short sentences, look at anything written by Apple:

  • The biggest thing to happen to iPhone since iPhone.”

  • All-new Lightning connector. Smaller. Smarter. Durable. Reversible.”

  • So much more than before. And so much less, too.”

That is just lovely.

We're throwing oh-so-many rules out the window at this point. But we are creating much more powerful copy.

When is a grammar “rule” not a rule?

A good client telling their freelance copywriter about the grammar rules they want them to follow
"Here are my personal grammar rules. No.1..."

When it's a personal preference, of course.

Many of the suggestions listed above are just that – suggestions. I would highly suggest factoring them into your advertising copy.

However, you also need to balance them against some other things:

1) Think about your brand

The biggest proviso with all of these marketing copy grammar rules is that if you don't like doing it, don't let it be done in your copy.

Your brand represents your company. You'll probably be happier if you are happy with it.

So, if you don't like split infinitives or sentences that begin with a conjunction, then that is a rule.


But be sure to tell your freelance copywriter about this if you're hiring one to create your copy.

This is why brand style guides are so useful – even if that guide is only half a dozen bullet points because you haven't really thought about it before now.

Because each brand and each client is different. Writers do not often intuit things through psychic means. Yet.

2) Consider your audience

For example, if you're having a conversation with friends over dinner, you might phrase something very differently to when you later have the same conversation with your boss.

Think about how your audience might expect to be spoken to and how they might relate to what you're saying.

If they can't relate, they won't conversate.

Or something slogan-like to that effect.

Learn to love short sentences in your advertising copy

Short sentences are better.

They're more powerful. They're easier to read online.

You might notice that very few paragraphs in this post are longer than two sentences. If they are, they tend to have at least one very short sentence in there.

That's not an accident.

The average person spends a lot of time interacting with websites, emails, and other content these days.

Big blocks of text are an instant turn-off. Your brain can't help but think: ugh, more of this?

But, like most of the rules listed here, this isn't set in stone.

Because, really, there aren't any hard-and-fast grammar rules for advertising.

If you think there are, be sure to tell any SEO copywriting agency you work with what you think they are.


Do you have your own advertising grammar rules?

Let me know what they are. Then we can create some killer copy together.

The Maiden Standard has been providing friendly and helpful SEO copywriting services to businesses in Bristol and beyond for over ten years.

Tell me about the places you need great copy today. Reach out to me at There's no obligation. Just a quick chat.

bottom of page