You can tell it's AI when it refuses to take a side and equivocally considers issues first on one hand and then the other hand, but can't get the number of fingers right.
Or as ChatGPT would put it:
Precise grammar and spelling are undeniably important, but minor imperfections in English rarely obstruct communication. As the most widely used language in the world, English is highly flexible, and most people navigate small errors without issue. For the majority of cases, a browser’s built-in proofreader is entirely sufficient.
On one hand, tools like ChatGPT can be valuable for refining text and ensuring clarity. On the other hand, frequent reliance on such tools can result in writing that feels formulaic, especially to those familiar with AI-generated styles. Balancing the benefits of polished phrasing with the authenticity of your own voice is often the most effective approach.