I’ll Instantly Know You Used ChatGPT

date
August 26, 2025
category
Artificial Intelligence
Reading time
5 Minutes

We’ve all sat in class and heard the warning: “No plagiarism. No ChatGPT. If you use AI, I’ll know.” Some students laugh it off. Others immediately start calculating if they can get away with it. But here’s the truth: most lecturers aren’t bluffing. And relying on AI alone for your assignments is a gamble you’ll probably lose.

Structure and Style Tells

AI frequently opens with predictable hooks such as “Have you ever wondered…?” or “What if I told you…?” These are recycled and lack originality. Another sign is random bolding or emphasis where it makes little sense, an odd stylistic quirk that pops up in some AI-generated work.

Lack of Personal Flourish

AI has trouble with emotional nuance. It doesn’t insert real sarcasm, annoyance, or small jokes that students often use. The tone stays flat, overly enthusiastic, or detached. Assignments generated by AI also tend to miss personal anecdotes, specific classroom context, or lived experience that human writers naturally bring in.

Hallucination and Fake Sources

AI is notorious for “hallucinating” sources. It will invent citations, scramble DOIs, or cite articles that don’t exist. This is one of the clearest giveaways, because lecturers can check the references quickly.

AI Detection Software: Helpful but Imperfect

Tools like Turnitin, GPTZero, Copyleaks, and Scribbr attempt to flag AI use, but none are perfect. Accuracy rates are inconsistent, and false positives occur often, especially for non-native English writers. However, when combined with lecturer intuition, these tools still provide strong clues.

Lecturer Intuition and Comparison

Lecturers can compare your past writing with your current assignment. If the voice suddenly shifts—different vocabulary, smoother structure, or an unusual level of sophistication—they can tell. Teachers who read hundreds of papers develop an instinct for spotting when something doesn’t fit.

Smarter Ways to Use AI

Instead of copying directly, students can use AI as a brainstorming partner, to simplify difficult concepts, or as an editing assistant. But the thinking and final voice should remain their own. AI works best when it supports learning, not when it tries to replace it.

Sources & Further Reading

  • Medium: “This is how you can tell that someone has used ChatGPT for writing the content”
  • Medium: “How I instantly know if someone used ChatGPT to write”
  • Tom’s Guide: “How to spot AI writing — 5 telltale signs to look for”
  • College Planning Source: “13 ways we can detect AI in college essays”
  • Wikipedia: “Hallucination (artificial intelligence)”
  • Wikipedia: “Artificial intelligence content detection”
  • arXiv: “Humans as AI Detectors” study
  • Reddit: “What are the most obvious signs that someone is using ChatGPT?”
written by
Sami Haraketi
Content Manager at BGI