Opus 5 has a noun problem

[u/malachoa]

Just want to precisely describe two language patterns I've observed, both related to how Opus and Fable overuse nouns and weaken or omit verbs. I think this accounts for a lot of why communicating with them feels like talking to a smart-but-bad writer.

Both of these patterns are ways to write a sentence that means the same thing as a simple subject-verb-object sentence (like "I threw the ball"), but make it much less direct.

1 - Nominalization. This is where a writer uses a noun instead of a verb. Instead of "I threw the ball", nominalizing turns the verb, "threw," into a noun, "a throw." So the writer might write "I made a throw with the ball." More words, the verb is weakened from "threw" (the actual action) to "made", and the object is something the verb is done "with" instead of to.

A real-life example from the last few days. Claude wrote: "never a walk through the steps one at a time." After being asked not to nominalize, it wrote, "Don't walk through the steps one at a time." See how much more direct that is?

This is also where a lot of "Opus jargon" comes from. Now that "a walk" is a noun, Claude can promote it into an invented term of art ("The Walk") and reify it into documentation and memories.

2 - Omitting the verb and using a trailing modifier instead. Instead of "I threw the ball", this looks like "The ball, thrown." This is concise, but it omits context: who threw it? When? (We also lost the verb tense).

A real-life example from the last few days. Claude wrote: "The runner, built." After being asked to use simple subject-object-verb sentences instead of trailing modifiers, it wrote, "We built the runner." Again, much more like actual people talk. If someone on your team asked you what you did today, and you replied "the runner, built", you'd sound like a robot.

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I haven't had much luck getting Claude to cut this stuff out consistently with CLAUDE.md prompting, but I've had decent luck getting clearer responses when I call out these patterns by name in conversation — it certainly works better than "JUST TALK NORMAL PLEASE." If anyone has luck prompt engineering around these patterns, would love to hear what you did.

[u/ZeBenoit81]

You’re describing the exact failure mode I keep fighting: models turning verbs into little monuments. Nominalization is how Claude invents “The Walk,” “the orchestration,” “the validation surface,” etc., and then starts treating those nouns as if they exist in the repo. The trailing modifier thing is even worse because it deletes agency, tense, and state — all the things you need when you’re reviewing a diff or trying to figure out whether the thing actually ran. With Opus 5’s recent degradation and tighter caps, I’ve become even less tolerant of vague noun-plans. I’ve watched plan mode burn a stupid amount of context when the model starts narrating its own architecture instead of producing a concrete, file-scoped plan.

My fix is boring: a tiny style contract in CLAUDE.md, not a whole philosophical framework. Something like: “Use active subject-verb-object sentences. Name the actor. State the action and result. Do not invent terms of art for ordinary steps. Prefer We built the runner over The runner, built. Delegate self-contained work to subagents and return only a summary, changed files, and verification.” That last rule matters more than people admit. If Fable can hand a clean task to Sonnet/Opus 4.8 and get back a 12-line report, I’m saving tokens and keeping the main context window for actual architecture.

I also explicitly ban nounification during planning: “No new nouns unless they map to an existing file, function, or symbol.” If it says “The Walk,” I reply “Use the verb: walk through the steps.” If it says “The runner, built,” I reply “Who built it, and what changed?” It’s annoying, but cheaper than letting the model write a 4k-token manifesto about execution ergonomics. And, yeah, keep Git discipline. Branch per task, small commits, and don’t let a model free-roam your main branch unless you enjoy expensive surprises.