A large group of everyday Polish "nouns" are not nouns at all — grammatically they are adjectives that have come to name a person or thing. Chory literally means "sick", but on its own it means "a patient"; znajomy means "familiar", but it also means "an acquaintance". The crucial fact, and the one English speakers consistently miss, is that these words keep adjective endings in every case. You don't decline chory like the noun kot; you decline it like the adjective dobry. Getting this wrong (widzę chora instead of widzę chorego) is one of the most reliable tells of a foreign speaker.
Why this category exists
Polish lets you turn an adjective into a noun simply by dropping the noun it modifies. Pokój dla chorych ludzi ("a room for sick people") shortens to pokój dla chorych ("a room for the sick / for patients"). Once the head noun disappears, the adjective carries the full meaning by itself — but it carries the original adjectival grammar with it. This is the same instinct English has in "the rich", "the unemployed", "the accused" — except English freezes those forms, while Polish makes them fully inflect for gender, number, and all seven cases.
The core test: it takes adjective endings
Compare a real masculine noun, kot ("cat"), with the substantivized adjective chory ("patient"). In the accusative singular they diverge completely:
| Case | Noun: kot | Substantivized adjective: chory |
|---|---|---|
| Nominative | kot | chory |
| Genitive | kota | chorego |
| Dative | kotu | choremu |
| Accusative | kota | chorego |
| Instrumental | kotem | chorym |
| Locative | kocie | chorym |
The endings -ego, -emu, -ym are pure adjective endings — identical to dobrego, dobremu, dobrym. A learner who treats chory as a noun produces forms like chora for the genitive, which is simply wrong.
Lekarz przyjmie teraz następnego chorego.
The doctor will see the next patient now.
Na oddziale leży dwóch ciężko chorych.
There are two seriously ill patients on the ward.
Rozmawiałem wczoraj z jednym znajomym z pracy.
I talked yesterday to an acquaintance from work.
The most common substantivized adjectives
These are not rare or literary — they are core vocabulary. Note that many have a clear masculine/feminine split, exactly as adjectives do.
| Word | Meaning as a noun | Literal adjective sense |
|---|---|---|
| chory / chora | patient (male / female) | sick |
| znajomy / znajoma | acquaintance | familiar, known |
| dorosły / dorosła | adult, grown-up | grown |
| uczony | scholar, scientist | learned |
| służący / służąca | servant / maid | serving |
| narzeczony / narzeczona | fiancé / fiancée | betrothed |
| księgowy / księgowa | accountant | (of) accounts |
| krewny / krewna | relative | related (by blood) |
| bezrobotny / bezrobotna | unemployed person | jobless |
| myśliwy | hunter | hunting |
Because these are adjectives, the feminine forms behave like feminine adjectives, not like feminine nouns. Księgowa ("a female accountant") declines exactly like the adjective nowa: genitive księgowej, accusative księgową, instrumental księgową.
Mój brat właśnie poznał swoją narzeczoną.
My brother has just introduced his fiancée.
Musimy zapytać księgową o ten rachunek.
We have to ask the accountant about this invoice.
Ten film jest tylko dla dorosłych.
This film is for adults only.
The plural is where it really shows
In the plural, the masculine-personal forms are unmistakably adjectival. "Two adults" is dwóch dorosłych — the genitive plural -ych, never a noun ending like dorosłów. The masculine-personal nominative plural also follows adjective rules: uczeni ("scholars"), chorzy ("patients"), with the softening you expect from masculine-personal adjectives.
| Case (plural) | masc-personal (dorosły) | non-masc-personal (chora, plural) |
|---|---|---|
| Nominative | dorośli | chore |
| Genitive | dorosłych | chorych |
| Dative | dorosłym | chorym |
| Accusative | dorosłych | chore |
| Instrumental | dorosłymi | chorymi |
| Locative | dorosłych | chorych |
Na konferencji wystąpiło kilku znanych uczonych.
Several well-known scholars spoke at the conference.
Bilety dla dwojga dorosłych i jednego dziecka, proszę.
Tickets for two adults and one child, please.
Surnames in -ski / -cki / -dzki are adjectives too
This is the single most useful application of the rule. Polish surnames ending in -ski, -cki, -dzki (and their feminine -ska, -cka, -dzka) are grammatically adjectives. Kowalski declines like polski: instrumental Kowalskim, genitive Kowalskiego. So "with Mr. Kowalski" is z panem Kowalskim — the instrumental adjectival -im, not a noun ending. The feminine Kowalska gives genitive Kowalskiej, accusative Kowalską.
Spotkałem się wczoraj z panem Kowalskim w urzędzie.
I met with Mr. Kowalski at the office yesterday.
To jest samochód państwa Nowakowskich.
This is the Nowakowskis' car.
Dzwoniłam do pani Wiśniewskiej w sprawie umowy.
I called Mrs. Wiśniewska about the contract.
This is also why a married couple's plural surname is Kowalscy (masculine-personal adjective plural), and "the Kowalskis" in the genitive is Kowalskich — never a noun-style plural. Place names work the same way: Zakopane (neuter adjective) gives do Zakopanego, w Zakopanem.
Some are fully lexicalized
A few of these words have drifted far enough from their adjective origin that speakers no longer feel the "missing noun". Księgowa and księgowy (accountant), narzeczony (fiancé), and myśliwy (hunter) are dictionary nouns in their meaning — yet they still decline as adjectives. Lexicalization changes the meaning, not the grammar. There is no shortcut here: you must simply remember that the adjectival inflection survives even when the word feels like a plain noun.
Common Mistakes
❌ Widzę chora w poczekalni.
Incorrect — noun-style accusative; should be the adjectival -ego
✅ Widzę chorego w poczekalni.
I see the patient in the waiting room.
❌ Rozmawiałem z panem Kowalskem.
Incorrect — invented ending; the surname is an adjective
✅ Rozmawiałem z panem Kowalskim.
I talked to Mr. Kowalski.
❌ Bilet dla dwóch dorosłów.
Incorrect — noun-style genitive plural; adjectives take -ych
✅ Bilet dla dwóch dorosłych.
A ticket for two adults.
❌ Zapytaj się księgowy o fakturę.
Incorrect — the feminine accountant is a feminine adjective: księgową
✅ Zapytaj się księgowej o fakturę.
Ask the accountant about the invoice.
❌ To jest dom Nowaków i Kowalsków.
Incorrect — -ski surnames don't take the noun plural -ów
✅ To jest dom Nowaków i Kowalskich.
This is the house of the Nowaks and the Kowalskis.
Note the last pair: Nowak is a genuine noun (genitive plural Nowaków), but Kowalski is an adjective (genitive plural Kowalskich). The two surname types in the very same sentence take different endings — which is exactly why you must classify each name before declining it.
Key Takeaways
- Words like chory, znajomy, dorosły, uczony, służący, narzeczony, księgowa, krewny are adjectives that name people or things; they keep adjective endings in every case.
- The diagnostic ending is the genitive/accusative masculine -ego (chorego), the instrumental -ym/-im (chorym, Kowalskim), and the genitive plural -ych (dorosłych) — never noun endings.
- Surnames in -ski/-cki/-dzki and many place names decline as adjectives; learn z panem Kowalskim as a model.
- Lexicalization (as in księgowa, narzeczony) changes meaning but not the adjectival grammar.
- For the full set of adjective endings these words borrow, see the full adjective declension; for surnames specifically, see personal-names declension.
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Start learning Polish→Related Topics
- Full Adjective Declension TablesA2 — The complete adjective paradigm across all seven cases and both numbers — and why it's the most regular, learnable part of the Polish case system.
- Declining First Names and SurnamesB1 — Polish inflects people's names by case just like any other noun — first names by ending and gender, -ski surnames like adjectives, and even foreign names take Polish endings.
- Noun-Forming Suffixes: -ość, -nik, -acz, -arzB1 — Polish builds nouns from adjectives and verbs with predictable suffixes — abstract -ość (always feminine), agent and instrument -nik/-acz/-arz/-ca, and the feminine -ka — so you can both decode and form whole families of words.
- Nominalization and Verbal-Noun ConstructionsC1 — How official and academic Polish turns whole clauses into noun phrases with verbal nouns in -anie/-enie/-cie — a dense nominal style and the C1 skill of decoding it.
- The Masculine-Personal Plural (Męskoosobowy)B1 — Polish plurals split into masculine-personal vs everything-else — and a single male human in the group flips the noun, adjective, verb, and pronoun.