ChatGPT-5 has been praised as OpenAI’s most “human-sounding” model yet, with sharper reasoning and smoother writing. But how well does it actually perform in business communication? In this article, I test ChatGPT-5 against Writing in Blue Ink’s PCA framework (purpose, clarity, and authenticity). The results reveal where AI can strengthen your writing, and where only the human touch can carry the message.

Plain language helps you write business content that's clear, confident, and easy to act on. Learn what it is, why it matters, and how to use it to improve emails, reports, proposals, and everyday communication.

Discover the 4 Ps of Purposeful Writing — Purpose, Person, Point, and Presentation — and learn how to craft clear, focused, and impactful messages that resonate with your readers. Perfect for professionals looking to improve their writing with intention and confidence.

Writing with purpose is the first step to better business communication. When drafting emails, reports, or proposals, knowing your “why” helps you write more clearly, stay focused, and connect with your readers. In this article, I share why purposeful writing matters, and how it improves clarity, tone, and impact in professional settings.