Why AI-Assisted Writing Gets Flagged — and How to Fix It

You wrote a draft, used AI to tidy it up, and now a detector is lighting up red. Frustrating — especially when the ideas are yours. The good news is that AI writing gets flagged for a small number of recognisable reasons, and most of them are fixable without losing your meaning or your citations.

1. Every sentence is the same length

This is the single biggest tell. AI tends to produce medium-length, evenly-paced sentences one after another. Detectors measure this as low "burstiness." Real writing mixes it up — a long, layered sentence, then a short, blunt one. When you read your draft aloud and it sounds like a metronome, that is the problem.

Fix: deliberately break the rhythm. Split a long sentence into two. Merge two short ones. Add a three-word sentence for emphasis. The content stays identical; the rhythm becomes human.

2. The phrasing is too smooth and generic

AI loves transitional scaffolding: "In today's fast-paced world," "It is important to note that," "Furthermore, by leveraging." These phrases are grammatically perfect and completely characterless. Because they are so predictable, they read as low-perplexity to a detector and as filler to a human reader.

Fix: cut the scaffolding and say the thing directly. "It is important to note that costs rose" becomes "Costs rose." You lose nothing but the padding.

3. There is no point of view

AI text often describes a topic from a neutral, encyclopedic distance. Human academic writing, even when formal, makes choices — it emphasises one factor over another, it argues, it draws a conclusion the writer clearly believes. That subjectivity is hard for AI to fake and easy for a reader to feel.

Fix: make sure your draft actually takes a position. What do you think matters most here, and why? Writing that commits to an argument reads as human because a person had to decide it.

4. You paraphrased instead of restructured

The most common mistake is running AI text through a synonym-swapper. This changes individual words but keeps the underlying sentence structure — so the rhythm and predictability that detectors measure barely move. The result often reads worse than the original and still gets flagged.

Fix: rewrite from the meaning of the paragraph, not word by word. Ask what the paragraph is trying to say, then say it again in your own structure. This is the difference between a paraphraser and a genuine rewrite — and it is what actually changes the signals a detector reads.

5. You never checked before submitting

Detectors disagree and false positives are real, so the worst position to be in is guessing. Running your final draft through a detector yourself — before your institution does — tells you exactly where you stand and which sentences still read as machine-made, so you can fix those specific lines.

PenSmith was built around this exact workflow: it restructures rhythm and register from the meaning up (not synonym by synonym), preserves your facts and citations, and lets you check the result against a built-in detector in the same place — so you submit something you can stand behind.