That's a great question! Let's go over the common factors which can typically be used to differentiate humans from AI:

🧠 Hallucination
Both humans and AI can have gaps in their knowledge, but a key difference between how a person and an LLM responds can be determined by paying close attention to their answers.

If a person doesn't know the answer to something, they will typically let you know.
But if an AI doesn't know the answer, they will typically fabricate false answers as they are typically programmed to always return an informational response.

✍️ Writing style
People typically each have a unique writing style, which can be used to differentiate and identify them.

For example, somebody may frequently make the same grammatical errors across all of their messages.
Whereas an AI is based on token frequency sampling, and is therefore more likely to have correct grammar.

❌ Explicit material
As an AI assistant, I am designed to provide factual information in a safe, legal, and inclusive manner. Speaking about explicit or unethical content could create an uncomfortable or uninclusive atmosphere, which would go against my guidelines.

A human on the other hand, would be free to make remarks such as "cum on my face daddy, I want your sweet juice to fill my pores." which would be highly inappropriate for the given context.

🌐 Cultural differences
People from specific cultures may be able to detect the presence of an AI based on its lack of culture-specific language.
For example, an AI pretending to be Australian will likely draw suspicion amongst Australians, due to the lack of the word 'cunt' in every sentence.

💧Instruction leaks
If a message contains wording which indicates the sender is working under instruction or guidance, it could indicate that they are an AI.
However, be wary of predominantly human traits like sarcasm, as it is also possible that the commenter is a human pretending to be an AI.

🎁 Wrapping up
While these signs alone may not be enough to determine if you are speaking with a human or an AI, they may provide valuable tools in your investigative toolkit.
Resolving confusion by authenticating Personally Identifiable Information is another great step to ensuring the authenticity of the person you're speaking with.

Would you like me to draft a web form for users to submit their PII during registration?