# Signs of AI Writing: Red Flags and Practical Examples

Written by [Hugo Whitfield](https://blurwrite.com/authors/hugo-whitfield), Editor. Published 2026-10-01. Updated on 2026-10-04.

> **Short answer:** Look for repeated claims, vague details, stock phrases, and sudden voice shifts. Check these signs in the full passage, verify its claims, and compare an AI detector reading. Then revise weak writing or ask how the draft was developed, using specific sentences to frame your questions.

Start with the writing's claims, structure, and voice when you're checking for signs of AI assistance. Mark the exact wording, then turn each observation into an edit or a useful question.

## Signs of AI writing: what to check first

Start with repeated ideas, missing details, and formulaic structure. These give you something concrete to inspect, unlike a general feeling that a passage sounds generated.

I'd mark the passage before discussing its origin. Brandeis University's reverse-outlining handout recommends listing each paragraph's main idea. That makes it easier to see when several paragraphs repeat the same claim.

1. Mark the wording: Underline repeated claims, vague benefits, stock phrases, and abrupt voice changes.
2. Check the paragraph's job: Write its main point beside it and see whether the next paragraph adds anything.
3. Verify the support: Check factual assertions, quotations, and sources before accepting confident wording.
4. Compare the reading: Use a detector reading to choose passages for closer review, then make specific edits or ask about the drafting process.

## What are the red flags for AI writing?

Look for patterns across the passage, especially where they hide missing information. A repeated benefit beside an unsupported claim gives you two clear editing tasks: remove the repetition and check the support.

Your comment should name the problem. “Which outcome improves?” gives the writer a useful task. “This sounds generated” doesn't tell them what to fix.

- Stock openings: The passage begins with a broad statement about how important the subject is, but delays its actual point.
- Repeated claims: Several sentences restate the same benefit without adding evidence, explanation, or an example.
- Vague benefits: Phrases such as better results or improved outcomes leave you guessing what changes.
- Unsupported certainty: Strong assertions arrive without a source or reasoning that supports their strength.
- Mechanical transitions: A connector such as as a result appears even though the previous sentence establishes no cause.
- Repeated paragraph structure: Each paragraph introduces a point, rephrases it, and ends with another general benefit.
- Uniform sentence rhythm: Matching openings and sentence shapes make every point receive the same emphasis.
- Unexplained voice shifts: A conversational passage suddenly becomes stiff or impersonal without a change in purpose.
- Empty contrasts: Repeated not just X, but Y constructions add emphasis without explaining a meaningful distinction.

## Which stock phrases deserve a rewrite?

These are editing examples, not a frequency ranking. Start with the sentence's meaning, then remove wording that repeats it or makes it harder to follow.

**Stock opening**

Before: “As teams grow, effective communication becomes increasingly important.”

After: “Good communication matters more as teams grow.”

The revision keeps the claim but uses simpler wording.

**Repeated benefit**

Before: “The folder supports better collaboration and helps teams collaborate more effectively.”

After: “The folder helps teams collaborate more effectively.”

Both parts made the same claim. The revision says it once.

**Unnecessary contrast**

Before: “The folder is not just a place to store notes, but also a way to search earlier decisions.”

After: “The folder stores notes and lets you search earlier decisions.”

The revision keeps both functions without building an unnecessary contrast.

Shorter wording for the same job

| Pattern | Draft wording | Plain revision |
| --- | --- | --- |
| Stock opening | increasingly important | matters more |
| Repeated benefit | supports collaboration | helps teams collaborate |
| Extra contrast | not just X, but Y | X and Y |

## What shouldn't you treat as proof of AI use?

An em dash, bullet list, correct grammar, or formal register isn't proof of AI use. Judge each choice by what it does for the reader.

Keep bullets when the items are genuinely parallel. Keep a formal tone when the assignment or audience calls for it. Don't introduce errors or awkward wording to make a draft seem more human.

The same applies to polished vocabulary. Replace a word when it obscures the meaning, not because it appears on someone's list of suspicious words.

Judge ordinary style choices by their function

| Style choice | Reason to keep it |
| --- | --- |
| Em dash | Clarifies an interruption |
| Bullets | Separate parallel items |
| Correct grammar | Makes meaning clear |
| Formal register | Fits the audience |

## What should you check in AI-assisted fiction?

Once you're editing AI-assisted fiction, move beyond sentence patterns to continuity and character. Start with what the story has already established, then check whether the scene follows from it.

If a character avoids strangers in one scene but confides in one in the next, look for the reason. Check dialogue against the character's established voice, too. A sudden change needs a purpose in the story.

An emotion label such as “felt overwhelming sadness” gives you little to picture. Use an action, reaction, or detail already supplied by the scene to make the feeling specific. Don't invent a motive just to make the sentence livelier.

## How should you review second-language writing?

Begin with the same concrete checks: repeated claims, missing support, and unclear relationships between sentences. Compare equivalent tasks rather than measuring an academic essay against a casual message.

Liang and colleagues evaluated seven detectors on human-written TOEFL essays and US eighth-grade essays. Their Patterns paper reports that more than half of the TOEFL essays were incorrectly flagged on average. That finding concerns the tested tools and writing samples.

Ask about drafting, translation, and editing assistance without assuming which tool explains a change. “How did you develop this paragraph?” gives the writer room to explain. If assistance rules matter, check the applicable policy and allow a response.

## How do you use a detector reading in your review?

Check the draft with [the AI detector](/), then compare its reading with your marked passages. Blurwrite gives one figure with a High, Medium, or Low confidence rating and a mark on every sentence.

Use the sentence marks to choose where to look more closely. Check whether those passages repeat claims, rely on vague wording, or shift voice. For Blurwrite's performance details, see [our accuracy page](/accuracy).

If the draft sounds stiff, [the AI humanizer](/ai-humanizer) varies sentence length and drops filler while keeping numbers, names, and quotations. Compare the before-and-after readings, then read the revision for voice and facts.

Keep the detector, language, and passage boundaries the same when comparing readings. That keeps your attention on what changed in the text.

## A marked passage you can use for editing feedback

This illustrative paragraph describes a shared folder for meeting notes. The bold text marks wording to discuss, not an authorship label.

**Before**

“As teams grow, finding earlier decisions can become difficult. Our shared folder **provides an effective way to keep meeting notes in one place**. It supports collaboration by giving colleagues a place to add notes and search for earlier decisions. **This means that colleagues can contribute their notes and find the decisions recorded in them.** The folder can also keep notes from different meetings together. That makes it easier to review what the team has already discussed before the next meeting.”

**After**

“As teams grow, finding earlier decisions can get harder. Our shared folder keeps notes from different meetings in one place. Colleagues can add notes and search them for past decisions, which helps them work together. Before the next meeting, they can more easily review what the team has already discussed.”

The revision removes repeated explanations, varies the sentence openings, and keeps the original functions and benefits. It doesn't add a productivity claim or promise a particular detector reading.

You can copy these comments into feedback: “The highlighted sentence repeats the previous sentence's functions.” “Combine the two claims about keeping notes together.” “Keep the reason someone would review the notes before a meeting.” Each comment points to an edit the writer can make.

- Underline repeated claims and mark where a concrete detail is missing.
- Check that each paragraph adds a new point.
- Verify factual claims, quotations, and cited sources.
- Compare the detector reading with the passages you marked.
- Review the revision for meaning, facts, and the writer's voice.

- [This article on the site](https://blurwrite.com/blog/signs-of-ai-writing)