The little word nie ("not, no") is written sometimes as one word with what follows (niedobry "not-good, bad") and sometimes as two (nie wiem "I don't know"). Which it is depends almost entirely on the part of speech of the next word — and getting it wrong is one of the most common spelling mistakes even native Poles make. The good news: the rule is mechanical once you can name the word class. This page gives you the decision table, the historical logic, and the two genuinely tricky cases (comparatives and participles).
Why part of speech decides it
The split reflects two different jobs nie does. When it negates a verb, it is a free-standing particle of sentence negation: it denies that an action happens, and it can be separated from the verb by other words. So it is written apart, like English not. But when it attaches to a noun, adjective, or adverb, it acts as a word-building prefix that creates a new lexical item with its own, often idiomatic, meaning — niepokój ("unrest, anxiety") is not merely "no peace," it's a noun in its own right. A prefix is part of the word, so it is written joined.
This is why the same root splits both ways depending on what class the word is in: nie wiem (verb, separate) but niewiedza ("ignorance," a noun, joined). Same nie, same root, opposite spelling — because one is a verb and the other is a noun.
Nie wiem, o co ci chodzi.
I don't know what you mean.
Jego niewiedza w tej sprawie była zaskakująca.
His ignorance in this matter was surprising.
Joined: nouns, adjectives, adverbs
Nie + noun → one word. The combination forms a new noun, frequently meaning "the opposite/absence of":
| Joined form | From | Meaning |
|---|---|---|
| niepokój | pokój (peace) | unrest, anxiety |
| nieprawda | prawda (truth) | untruth, falsehood |
| nieszczęście | szczęście (luck) | misfortune |
| niezgoda | zgoda (agreement) | discord |
Czuję jakiś niepokój, nie wiem dlaczego.
I feel a kind of unease, I don't know why.
Nie + adjective → one word. This creates the negative/antonym adjective:
| Joined form | From | Meaning |
|---|---|---|
| niedobry | dobry (good) | not good, bad, nasty |
| niemały | mały (small) | not small, sizeable |
| niedrogi | drogi (expensive) | inexpensive |
| niemożliwy | możliwy (possible) | impossible |
To był niemały wydatek, ale warto było.
It was no small expense, but it was worth it.
Nie + adverb (derived from an adjective) → one word. Adverbs in -o or -e built from adjectives join too:
| Joined form | From | Meaning |
|---|---|---|
| niedobrze | dobrze (well) | not well, badly; (I feel) unwell |
| niedaleko | daleko (far) | not far, nearby |
| niewiele | wiele (much) | not much, little |
Sklep jest niedaleko, dojdziemy pieszo.
The shop is not far, we'll get there on foot.
Zrobiło mi się niedobrze po tej jeździe.
I started feeling unwell after that ride.
Separate: verbs, numerals, pronouns, prepositions
Nie + verb → two words. This is sentence negation and is always written apart. It covers all finite verb forms, infinitives, and gerunds:
Nie chcę cię niepokoić, ale mamy problem.
I don't want to alarm you, but we have a problem.
Wolę nie mówić o tym teraz.
I'd rather not talk about it now.
Notice in the first example both spellings at once: nie chcę (verb → separate) and niepokoić — here joined because niepokoić is a single verb meaning "to alarm," not nie + pokoić. The lesson: write nie apart only when it negates the verb; if the verb already has nie baked into its lexical meaning, there is nothing to separate.
Nie + numeral → two words (used contrastively, "not five"):
Przyszło nie pięć osób, tylko piętnaście.
Not five people came, but fifteen.
Nie + pronoun → two words:
To nie ja stłukłem ten talerz.
It wasn't me who broke that plate.
Nie + preposition → two words (negating a phrase): nie do wiary ("unbelievable, not to be believed"), nie z tej ziemi ("out of this world").
To jedzenie jest nie z tej ziemi!
This food is out of this world!
The two genuinely tricky cases
1. Comparatives and superlatives — separate when contrastive. With the comparative or superlative degree, nie is normally written separately, especially when an explicit contrast ("not X, but Y") is present:
Ten film jest nie lepszy, ale gorszy od poprzedniego.
This film is not better but worse than the previous one.
Wybierz coś nie najdroższego, mamy mały budżet.
Pick something not too expensive, we're on a small budget.
Here nie lepszy and nie najdroższego stay apart because nie sets up a contrast against the comparative degree rather than forming a fixed antonym. (Contrast the plain positive adjective, which joins: niedobry.)
2. Adjectival participles — now joined. Polish spelling reform settled a long-debated point: present and past adjectival participles (the -ący / -ony / -ny / -ły forms used like adjectives) are written joined with nie, just like ordinary adjectives.
| Joined form | From participle | Meaning |
|---|---|---|
| niepalący | palący (smoking) | non-smoking |
| niezadowolony | zadowolony (satisfied) | dissatisfied |
| nieznany | znany (known) | unknown |
Proszę o stolik w części niepalącej.
A table in the non-smoking section, please.
Aktor wciąż jest szerzej nieznany.
The actor is still not widely known.
Common Mistakes
❌ Niewiem, gdzie są klucze.
Incorrect — wiedzieć is a verb, so nie is written separately.
✅ Nie wiem, gdzie są klucze.
I don't know where the keys are.
The single commonest error: gluing nie onto a verb. Wiem is a verb form, so nie stands apart — nie wiem, always two words.
❌ Ona jest nie miła dla sąsiadów.
Incorrect — miły is an adjective, so nie joins: niemiła.
✅ Ona jest niemiła dla sąsiadów.
She is unkind to the neighbours.
The mirror error: splitting nie from an adjective. Miła is an adjective, so the negative is the joined word niemiła.
❌ Czuję pewien nie pokój.
Incorrect — niepokój is a single noun and must be written joined.
✅ Czuję pewien niepokój.
I feel a certain unease.
Niepokój is one noun ("anxiety"), not nie + pokój ("no peace"); the joined form is required.
❌ To niedziałało tak, jak chcieliśmy.
Incorrect — działać is a verb, so nie stays separate.
✅ To nie działało tak, jak chcieliśmy.
It didn't work the way we wanted.
A verb again — działało is past-tense działać, so nie is written apart.
❌ Wolę miejsce dla nie palących.
Outdated — modern spelling joins the participle: niepalących.
✅ Wolę miejsce dla niepalących.
I prefer a place for non-smokers.
Adjectival participles join with nie in modern Polish. The split spelling is pre-1997 and now counts as an error.
Key Takeaways
- The spelling of nie depends on the part of speech of the next word.
- Joined: nouns (niepokój), adjectives (niedobry), adjective-derived adverbs (niedaleko), and adjectival participles (niepalący, nieznany).
- Separate: verbs (nie wiem), numerals (nie pięć), pronouns (nie ja), prepositions (nie z tej ziemi).
- Comparatives/superlatives take nie separately when contrastive (nie lepszy, ale gorszy).
- The same root can go both ways depending on its class: nie wiem (verb) vs niewiedza (noun).
Now practice Polish
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Start learning Polish→Related Topics
- Basic Negation with nieA1 — How to negate Polish verbs and other words with nie — placed directly before the negated word, with no auxiliary 'do', and how moving nie changes the meaning.
- Word Formation: OverviewB1 — Polish builds its huge, transparent vocabulary from roots plus prefixes and suffixes — learning the affix system multiplies your effective vocabulary far more than rote memorisation.
- The Comparative: -szy / bardziejA2 — How Polish forms 'bigger, taller, more interesting' — the synthetic -szy/-ejszy suffix with stem mutation, the analytic bardziej type, and the four high-frequency irregulars.
- The Active Adjectival Participle (-ący)B2 — The present active participle in -ący/-ąca/-ące ('reading', 'running') — formed from imperfective verbs, it declines like an adjective and agrees with its noun, one of three distinct Polish '-ing' forms.
- Negating Specific Words and ContrastB2 — Constituent (partial) negation — putting nie before a non-verb to negate just that piece — plus the nie…, ale/lecz frame and intensifiers like nie bardzo, wcale nie, and bynajmniej.