You can tell within a sentence. There is a particular flatness to AI writing that has nothing to do with grammar and everything to do with what the model was working from.
Read enough AI-written copy and you develop an instinct for it. Not for any particular word, though there are words. For something underneath.
The paragraphs are all roughly the same length. The sentences are all roughly the same length. Every point arrives with equal weight, as though nothing in the piece mattered more than anything else. It opens by telling you what it is about to say. It closes by telling you what it just said, then adds an upbeat line about the future.
None of that is a grammatical error. It is a rhythm problem, and rhythm is how readers recognise a person.
Real writing is uneven. Someone who knows their subject spends four hundred words on the part that matters and forty on the part that does not. They contradict themselves and then resolve it. They use a specific number because they know the number. That unevenness is the sound of someone deciding what to emphasise, and a model with nothing to emphasise cannot produce it.
The reflex is to blame the model. Try a better one, write a longer prompt, add "write like a human" and hope.
It rarely works, because the model is not the constraint. Consider what you actually gave it.
You gave it a topic. Perhaps a tone word. Perhaps a sentence about your company. From that it has to infer what your business does, what you sell, what you would never claim, who is reading, what they already believe, what would move them, and how the argument should be built.
It cannot infer any of that, so it does what anyone would do with no information: it writes the safest possible version. The average of everything written about that topic. Which is exactly what it sounds like.
A better model with the same brief gives you a more articulate average.
Ask a copywriter to write a piece and they will not start writing. They will ask questions, and the questions are always the same shape.
What does the business actually do? Not the positioning line. What it sells, to whom, at what price, and what happens when someone buys.
How does this brand sound? Not "professional and friendly", which describes most brands. A brand that behaves like a challenger writes differently from one that behaves like an expert. That difference runs through sentence length, vocabulary, what gets stated as fact and what gets argued.
Who is reading this? Not a demographic. What they are trying to do, what is stopping them, and what a win looks like from where they sit.
And how do they take information? This is the question most briefs miss. Some readers want the outcome in the first line and will decide from there. Others will not move until they have seen the reasoning. Same facts, different argument.
What shape should the argument take? Problem then agitation then solution is a different piece from features then advantages then benefits. Copywriting frameworks have had these structures for decades because they work.
Answer those, and the writing is half done. Skip them, and no amount of prompting recovers it.
Here is the part that makes it worse.
Suppose you do write the full brief. You paste in your business description, your brand voice, your audience, your framework. The output is markedly better.
Tomorrow you open a new chat and it is gone. So you do it again. And the version you paste tomorrow is not quite the version you pasted today, because you are retyping from memory. A month later, three people are pasting three different descriptions of the same brand.
That is how a company ends up sounding like two different companies across two channels. Not because anyone wrote badly, but because the context was reassembled by hand every time and drifted a little on each pass.
The fix is not discipline. It is storage. The brand, the audiences and the way they should be spoken to belong in one place that every piece is written from, rather than in a paragraph someone remembers to paste.
Four things, in order of how much difference they make.
Give it the business. What you actually sell, in real terms. The single biggest lift, because it stops the model reaching for generic advice and lets it write towards something specific.
Give it a voice with a character. Not adjectives. A way of thinking that carries through every sentence, held consistently rather than described again each time.
Give it the reader, properly. What that person is trying to do and how they prefer to be persuaded. This changes what leads, what gets emphasised and what gets left out, which is far more than tone.
Give it a structure. A proven copywriting framework, applied step by step, so the argument goes somewhere rather than circling.
Then read what comes back and fix what is wrong, because you know things the model does not. That last step is not a failure of the tool. It is the job.
A reference guide to the model BraVo runs on, and what each layer actually changes about the words that come out.
Nobody signs off alone. So why does almost every campaign speak to a single imagined reader?
BraVo holds your business, your brand and your audiences, and writes from them. Set it up once.