How to Stop ChatGPT Using Repetitive Writing Patterns

Why Does ChatGPT Do This?

OpenAI hasn't explained it. The usual explanation, which is plausible but unconfirmed, is that the training data contains a lot of marketing copy and persuasive writing, where punchy contrast-driven sentences are common, and that feedback-based fine-tuning rewarded confident, structured prose over plain prose.

The result: ChatGPT defaults to rhetorical flourishes even when you want something plain and direct. The pattern has no official name, but the r/ChatGPT community (1,645 upvotes on the original thread) has dubbed it "AI em-dash syndrome" or simply "the ChatGPT sentence."

The Most Common Patterns to Watch For

• "It's not just X — it's Y." The original offender. Shows up in almost every persuasive or summary response.
• Em-dash mid-sentence pivots. "You need speed — but you also need reliability." Endless variations of this structure.
• Triple-bullet openings. Responses that start with three bullet points regardless of whether a list is appropriate.
• Conclusion summaries. "In summary, …" followed by a restatement of everything already said.
• Hollow affirmations. "Great question!" or "Absolutely!" at the start of a reply — especially in older model versions.

How to Fix It: Custom Instructions

Go to Settings → Personalization → Custom Instructions (or the system prompt in your API/operator setup) and paste the following:

Short version (recommended for most users)

Write plainly and directly. Avoid the "It's not just X — it's Y" sentence pattern. Do not open responses with affirmations like "Great question!" or "Absolutely!". Skip summary conclusions unless I ask for one.

Full version (for writing-heavy workflows)

Writing style rules — follow these in every response:
- No "It's not just X — it's Y" constructions.
- No em-dash pivots used as a rhetorical device.
- No opening with bullet lists unless the request is explicitly a list.
- No filler affirmations (Great question, Absolutely, Certainly, Of course).
- No summary paragraph at the end unless I ask for a summary.
- Prefer active voice. Prefer specific nouns over abstract ones.
- If you are uncertain, say so plainly instead of hedging with "It's worth noting that…"

What If the Pattern Keeps Appearing?

If ChatGPT reverts to old habits mid-conversation, you can nudge it in-chat: "Reminder: plain writing, no rhetorical contrasts." For a shared workflow, put the style rules in the Project's instructions or in a plugin's skill so everyone using it gets them. Custom GPTs retire on Dec 11, 2026, so don't start new ones. Custom instructions allow 1,500 characters on Free and Go and 5,000 on paid plans (OpenAI), so the short version above fits anywhere.

Also note that the pattern is more pronounced in shorter, summary-style prompts. If you give ChatGPT more context and a specific tone target ("write like an engineer's internal Slack message"), it calibrates away from marketing-speak more reliably.

Does This Affect Quality?

No — suppressing these patterns does not reduce response accuracy. You are only changing surface style, not the underlying reasoning. Most users report that plain-writing instructions produce clearer outputs because ChatGPT is forced to be specific rather than rhetorical.