A script that reads well on the page can be unwatchable in the mouth. The tells below are what make a talking-head video sound like someone reciting rather than talking, and most of them are what an LLM produces by default.

This file is self-contained. For the general, always-moving list of LLM writing tells, re-read the live article rather than trusting a snapshot:

skills/yap-writer/scripts/fetch_ai_tells.sh /tmp/tells.txt

It exits non-zero and says so if Wikipedia is unreachable; that is a freshness check failing, not this file becoming invalid. Technique from jbaruch/blog-writer — see CREDITS.md.

The rhythm tells

The tricolon. Three balanced clauses, escalating.

It's not about the tool. It's not about the workflow. It's about the mindset.

Nobody talks like this. It is the single loudest tell in spoken AI copy, and it is seductive because it scans well silently. One clause, or two that are deliberately unbalanced.

Perfect antithesis. "Not X, but Y." Once in a script is a rhetorical choice. Twice is a pattern. Three times and the viewer can hear the machine.

Every sentence the same length. Real speech lurches — a nine-word sentence after a two-word one. Uniform sentence length is the prosodic equivalent of a monotone.

The vocabulary tells

Words that appear in spoken scripts far more often than in speech:

delve, landscape, realm, testament, crucial, pivotal, robust, seamless, leverage (as a verb), navigate (figurative), unlock, harness, elevate, foster, underscore, myriad, plethora

And the connective scaffolding nobody says out loud:

moreover, furthermore, additionally, consequently, in conclusion, it's important to note, it's worth noting, that being said

If you would not say it to a friend in a bar, cut it.

The structure tells

Announcing the structure. "There are three things I want to cover today. First..." That is a document read aloud. A person makes the point and moves.

The summary close. "So to recap, we covered X, Y and Z." Nobody recaps a 90-second video. The close is application or next steps, not a table of contents in reverse.

No false starts, ever. A script with zero self-correction, zero asides, zero "actually — " reads as recited because it is. Leave one in on purpose.

Hedging that costs nothing. "It can often be the case that..." Speech commits. Say the thing.

The punctuation that becomes a tell out loud

Em-dashes doing the work of a pause. On the page a dash is elegant. Read aloud, a script full of them produces a strange stop-start cadence, because the writer used punctuation where a speaker would use a shorter sentence. If a line has two dashes, it is two sentences.

Semicolons. There is no spoken semicolon.

Parentheticals. A speaker cannot signal a bracket. Either the clause matters, in which case it is a sentence, or it does not, in which case cut it.

What real speech has that scripts lack

Contractions. Always. "Do not" in a script becomes a stilted read.
Specific numbers over round ones. "Fifty-eight minutes" is heard as true; "about an hour" is heard as filler.
One idea per sentence. Subordinate clauses are for readers who can go back.
Repeating a word instead of reaching for a synonym. Elegant variation is a writing habit and it sounds evasive out loud.

The test

Read the draft aloud, at pace, standing up. Every place you stumble, re-read, or run out of breath is a place the sentence was built for the eye. Cut it and say what you actually meant.

That test outranks everything above. A script that passes the read-aloud and breaks three rules here is fine; a script that follows every rule and cannot be spoken is not.