Show HN: Finnish Humanizer – 26 patterns for detecting AI-generated Finnish text
HarriSipola Sunday, February 22, 2026Finnish is morphologically complex — vowel harmony, six grammatical cases, free word order. AI models get it wrong in the same predictable ways every time.
I built this after noticing that AI-generated Finnish triggers immediate pattern recognition in native speakers: overly formal register,
SVO word order (Finnish allows much more variation), missing discourse particles (-han/-hän, -pa/-pä), and excessive nominalization.
Before:
"Tämä on erittäin merkittävä kehitysaskel, joka tulee vaikuttamaan laajasti alan tulevaisuuteen. On syytä huomata, että kyseinen
innovaatio tarjoaa lukuisia mahdollisuuksia eri sidosryhmille."
After:
"Iso juttu alalle. En ole varma mihin tämä lopulta johtaa, mutta hyötyjiä on – varsinkin ne jotka ovat odottaneet tällaista jo vuosia."
Finnish Humanizer is a pattern library — 26 identified patterns — packaged as a Claude Code skill and distributed for 15 platforms
(Cursor, Copilot, Windsurf, ChatGPT custom instructions, etc.). It's not an additional model call. It's a checklist of linguistic tells
you can apply mechanically.
Patterns are grounded in Finnish linguistics research (Kotus — the Research Institute for the Languages of Finland).
Would especially value feedback from Finnish speakers on pattern coverage and any false positives.
Summary
The Finnish Humanizer is an open-source library that provides a set of tools for humanizing data, such as converting numbers to words and generating realistic-looking names and addresses. It aims to make data more readable and accessible for users.
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github.com