The negative participle ends in -maton / -mätön and turns a verb into a negative adjective: syömätön "uneaten," tuntematon "unknown," puhumaton "not speaking / taciturn," väsymätön "tireless," loppumaton "endless." It is the Finnish counterpart of the English prefix un- and the suffix -less rolled into one — and, crucially, it is a single word. Where English needs a phrase ("not yet done," "not able to be drunk"), Finnish packs the negation, the verb, and the adjective ending into one form. This is the sixth participle in the participle system, the only one that is inherently negative.
How it is built: the -ma stem plus the caritive -ton
The suffix decomposes cleanly into two familiar pieces: the -ma-/-mä- stem (the same base as the agent participle and the third infinitive tekemään) plus the caritive suffix -ton/-tön ("without"). So tehdä → tekemä- → tekemä + tön = tekemätön. Take the third-infinitive stem and hang the caritive ending on it.
| Verb | -ma stem | Negative participle | Meaning |
|---|---|---|---|
| puhua (speak) | puhuma- | puhumaton | not speaking, taciturn |
| syödä (eat) | syömä- | syömätön | uneaten |
| tehdä (do) | tekemä- | tekemätön | undone, not done |
| tuntea (know) | tuntema- | tuntematon | unknown |
| väsyä (tire) | väsymä- | väsymätön | tireless |
| loppua (end) | loppuma- | loppumaton | endless, unending |
| maksaa (pay) | maksama- | maksamaton | unpaid |
Two things fall out automatically. Vowel harmony decides -maton (back vowels: puhumaton, loppumaton) versus -mätön (front vowels: syömätön, väsymätön). And the strong grade is kept, exactly as in the third infinitive: ottaa → ottamaan → ottamaton "not taken" keeps the tt; hakea → hakemaan → hakematon "not fetched" keeps the k. No gradation weakens the -ma stem.
Pöydällä oli lautasellinen syömätöntä ruokaa.
On the table was a plateful of uneaten food.
Tekemätön työ ei katoa itsestään.
Work left undone doesn't disappear on its own.
It is an adjective — so it declines
Like every participle, -maton is a full adjective and agrees with its noun in case and number. Here is where the form gets its reputation for being tricky: the oblique stem is -ttoma-/-ttömä-, with the single t doubling to tt. This is the same inverse pattern as the caritive adjectives such as onneton → onnettoman (see adjective derivation).
| Case | Singular | Plural |
|---|---|---|
| Nominative | tuntematon | tuntemattomat |
| Genitive | tuntemattoman | tuntemattomien |
| Partitive | tuntematonta | tuntemattomia |
| Inessive | tuntemattomassa | tuntemattomissa |
Notice the shape shifts: nominative tuntematon (single t), but genitive tuntemattoman and partitive plural tuntemattomia (double tt). The partitive singular keeps the n: tuntematon → tuntematonta, tekemätön → tekemätöntä.
Poliisi selvittää tuntemattoman miehen henkilöllisyyttä.
The police are working out the identity of an unknown man.
Sain viestin tuntemattomasta numerosta.
I got a message from an unknown number.
Two readings: "un-X-ed" and "un-X-able"
The same form covers two English ideas, and context decides which. With a transitive verb, the default reading is the negative of the past passive participle: luettu "read" → lukematon "unread," maksettu "paid" → maksamaton "unpaid." The action simply has not happened yet.
Pöydällä oli pino lukemattomia kirjeitä.
On the table was a stack of unread letters.
Vuokra on yhä maksamatta — lasku on maksamaton.
The rent is still unpaid — the bill is unpaid.
But with many verbs the form slides into a potential "-able" reading: uskoa "believe" → uskomaton "unbelievable," käsittää "grasp" → käsittämätön "incomprehensible," korvata "replace" → korvaamaton "irreplaceable." And juomaton vesi means water that one does not / cannot drink — "undrinkable water."
Se oli aivan uskomaton tarina.
It was an absolutely unbelievable story.
Kaivon vesi oli juomatonta.
The well water was undrinkable.
With an intransitive verb, the reading is "that does not / cannot X": väsyä "get tired" → väsymätön "that doesn't tire, tireless"; loppua "run out" → loppumaton "that doesn't end, endless."
Väsymätön vapaaehtoinen jakoi ruokaa koko illan.
The tireless volunteer handed out food all evening long.
Loppumaton jono kiemurteli pitkin katua.
An endless queue snaked along the street.
The caritive family it belongs to
-maton is the verbal member of a wider caritive ("without-") family. From a noun, -ton/-tön builds the plain caritive adjective: raha "money" → rahaton "penniless," onni "luck" → onneton "luckless, miserable," koti "home" → koditon "homeless." From a verb's -ma stem you get -maton. And its close adverbial cousin is the third-infinitive abessive -matta/-mättä "without doing" — tekemättä "without doing," syömättä "without eating."
Keep the two verbal forms apart: tekemätön is an adjective ("undone work," tekemätön työ), while tekemättä is an adverb ("he left without doing it," hän lähti tekemättä sitä). Same -ma root, different endings, different jobs.
Hän lähti töihin syömättä aamiaista.
She left for work without eating breakfast.
Common Mistakes
❌ Ovi oli ei avattu koko päivän.
Incorrect — don't negate a participle with ei; use the -maton form: avaamaton.
✅ Ovi oli avaamaton koko päivän.
The door stayed unopened all day.
❌ Poliisi etsii tuntematoman miehen.
Incorrect — the oblique stem doubles the t: tuntemattoman.
✅ Poliisi etsii tuntemattoman miehen.
The police are looking for an unknown man.
❌ Ruoka jäi syömaton lautaselle.
Incorrect — a front-vowel verb needs -mätön, and the case must agree: syömättä / syömätön.
✅ Ruoka jäi syömättömäksi lautaselle.
The food was left uneaten on the plate.
❌ Se on epäuskottu tarina.
Incorrect — 'unbelievable' from a verb is the -maton participle, not an epä- coinage: uskomaton.
✅ Se on uskomaton tarina.
It's an unbelievable story.
Key Takeaways
- Formation: the -ma-/-mä- stem (the third-infinitive base) + the caritive -ton/-tön: tekemä + tön = tekemätön.
- Harmony gives -maton vs -mätön; the strong grade is kept (ottamaton, hakematon).
- It declines like onneton: oblique stem -ttoma-/-ttömä- with a doubled tt — tuntemattoman, tuntemattomia.
- One form, two readings: "un-X-ed" (lukematon "unread") and "un-X-able" (uskomaton "unbelievable"); context decides.
- Don't reach for ei
- participle or epä- — -maton is the one-word negator.
Now practice Finnish
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Finnish→Related Topics
- Participles: An OverviewB1 — The map of Finnish participles — verbal adjectives that decline and agree: present/past active, present/past passive, agent (-ma) and negative (-maton).
- Adjective Suffixes: -inen, -llinen, -ton, -mainenB1 — The main adjective-forming suffixes of Finnish — -inen, -llinen, the caritive -ton/-tön, and the resemblance suffix -mainen — with the having-vs-without pairs they build.
- Participles Used as AdjectivesC1 — All four Finnish participles can modify a noun like an adjective — tuleva viikko, tehty työ, syötävä sieni — agreeing in case and number.
- Negation Beyond the VerbA2 — Finnish negation is a clause-wide system, not one word: the negative verb agrees for person, and negation also forces partitive objects, negative concord, and fused eikä coordination.
- Deriving Adjectives: -llinen, -ton, -mainenB2 — Finnish builds adjectives with productive suffixes: -llinen 'having', -ton 'without' (työtön → työttömän), -mainen '-like', plus -kas and -isa.