How To Write With An LLM

# How To Write With An LLM Source: [https://simonwillison.net/2026/Sep/17/how-to-write-with-an-llm/](https://simonwillison.net/2026/Sep/17/how-to-write-with-an-llm/) 17th September 2026 \- Link Blog **[How To Write With An LLM](https://sockpuppet.org/blog/2026/09/17/how-to-write-with-an-llm/)**\. Thomas Ptacek on using LLMs as copyeditors, not as writing assistants: > **Rule Number One: You may not use a single word an LLM suggests to you\.** \[\.\.\.\] I think that as a form of intellectual personal protective equipment you should adopt the rule that any specific turn of phrase an LLM suggests is off limits\. Be strict about the rule\! I won't let LLMs write content for my blog, but I use them for fact\-checking, spelling and grammar and as an occasional thesaurus \(see[my proofreading prompt](https://simonwillison.net/guides/agentic-engineering-patterns/prompts/#proofreader)\)\. The rule to never use a turn of phrase suggested by an LLM feels good to me\. The text has that weird smell to it, and it's also a good principle to help stay disciplined\. Later in this piece Thomas shows a screenshot of his personal LLM copyediting tool \(see also[this Twitter thread](https://x.com/tqbf/status/2100414465187475821)\), and provides a prompt to help kickstart building your own\.