GrammarNoun Declension

Declension (склоне́ние существи́тельных) is the way a Russian noun changes its ending to show its job in the sentence. English keeps the noun the same and relies on word order and little words like of, to and with. Russian instead rewrites the end of the word:

• Э́то стол. (This is a table.) — the table is the subject
• но́жка стола́ (the leg of the table) — “of the table”
• Я иду́ к столу́. (I am walking to the table.) — “to the table”
• кни́га на столе́ (a book on the table) — “on the table”

It is the same word стол every time, but its ending tells you what it is doing. Russian has six cases — Nominative, Genitive, Dative, Accusative, Instrumental and Prepositional — and every noun has a form for each of them, in the singular and in the plural.

Three declension classes

You do not learn a separate set of endings for every noun. Nearly all Russian nouns fall into just three declension classes, and a noun's class is decided mainly by its gender and its nominative ending:

Notice that gender and class are not the same thing. Feminine nouns are split between the 1st declension (ма́ма) and the 3rd (ночь), and masculine nouns are split between the 1st (па́па) and the 2nd (стол). To place a noun you look at its ending, not only its meaning.

Watch out for masculine -а / -я nouns. Words like па́па (dad), дя́дя (uncle) and мужчи́на (man) are masculine by meaning but decline exactly like ма́ма — they belong to the 1st declension.

Hard stems and soft stems

Within a class, the exact vowel in the ending depends on whether the stem is hard or soft. The two are mirror images: where a hard noun has -а / -о / -ы / -у, a soft noun has the softened partner -я / -е / -и / -ю.

• Hard: the stem ends in a plain consonant — стол, ма́ма, окно́.
• Soft: the stem ends in -й, -ь or a soft-signalling vowel letter — музе́й, неде́ля, мо́ре.

Compare the hard ма́ма with the soft неде́ля: ма́ма vs неде́ля, ма́мы vs неде́ли, ма́му vs неде́лю. The endings match position for position — only the hardness of the vowel changes.

1st declension — singular

The 1st declension covers nouns ending in -а (hard) or -я (soft). Here are a hard feminine noun, ма́ма (mum), and a soft one, неде́ля (week), side by side:

The 1st declension is the only class with its own special accusative ending: -у / -ю (ма́му, неде́лю). Dative and prepositional are identical here (ма́ме), which is normal and nothing to worry about.

2nd declension — masculine singular

Masculine nouns ending in a consonant or -й belong to the 2nd declension. Their nominative has a zero ending (nothing after the stem), and the other cases add endings onto the full stem. Compare the inanimate стол (table) with the animate брат (brother):

The key difference is the accusative: for an inanimate noun it copies the nominative (стол), but for an animate noun it copies the genitive (бра́та). We come back to this rule below. The soft masculine музе́й (museum) works the same way: музе́я, музе́ю, музе́й, музе́ем, (о) музе́е.

2nd declension — neuter singular

Neuter nouns in -о / -е share the 2nd declension with masculine nouns; only the nominative and accusative look different. Compare the hard окно́ (window) and the soft мо́ре (sea):

Neuter nouns are almost always inanimate, so their accusative always equals the nominative (окно́, мо́ре). Note the stress jump in окно́: it sits on the ending in the singular (окно́, окна́, окну́) but moves to the stem in the plural (о́кна).

3rd declension — singular

The 3rd declension holds feminine nouns ending in a soft sign -ь, such as ночь (night), две́рь (door) and тетра́дь (notebook). This is the smallest class and its endings are quite different from the 1st declension:

Two features stand out. Genitive, dative and prepositional all merge into a single -и (но́чи), and the instrumental has the distinctive ending -ью (но́чью) — not the -ой of the 1st declension. Do not confuse these -ь nouns with masculine soft-sign nouns like день (day), which are masculine and follow the 2nd declension.

The accusative and the animacy rule

The accusative is the case of the direct object — the thing an action is done to. For masculine and neuter nouns its form depends on whether the noun is animate (a living being) or inanimate (a thing):

• Inanimate masculine/neuter: Accusative = Nominative. Я ви́жу стол. (I see the table.)
• Animate masculine: Accusative = Genitive. Я ви́жу бра́та. (I see my brother.)

Feminine -а / -я nouns are the exception: they have their own accusative ending -у / -ю regardless of animacy, so the animacy rule does not touch them in the singular:

• Я ви́жу ма́му. (I see mum.) — animate, but still just -у
• Я чита́ю кни́гу. (I am reading a book.) — inanimate, also -у

The full picture, including how animacy behaves in the plural, is in the accusative case article.

Spelling rules that bend the endings

Some endings look slightly different for spelling reasons, not grammatical ones. The most important is the 7-letter (spelling) rule: after г к х ж ч ш щ you must write -и instead of -ы.

• кни́га → кни́ги (book → of the book), never *кни́гы
• де́вушка → де́вушки (girl → of the girl), never *де́вушкы
• но́га → но́ги (leg → of the leg)

The same rule reshapes the nominative plural: кни́ги, де́вушки, ру́чки all take -и. A companion rule affects the letter о: after the hushing consonants ж ч ш щ ц an unstressed о becomes е, which is why the instrumental of муж is му́жем (not *му́жом) but оте́ц gives stressed отцо́м.

The plural

The plural has its own set of endings. The easiest to learn is the nominative plural, which marks “more than one”:

Below the nominative, the plural endings become remarkably uniform across all genders. Here is the full plural of стол:

The dative -ам / -ям, instrumental -ами / -ями and prepositional -ах / -ях are the same for every noun, which makes most of the plural easy once you know them.

The genitive plural — the hardest ending

The one plural form that really has to be learned is the genitive plural, because its ending depends on the class:

• Masculine (hard): -ов — стол → столо́в, студе́нт → студе́нтов.
• Masculine (soft) & 3rd declension feminine: -ей — музе́й → музе́ев, ночь → ноче́й, день → дней.
• Feminine -а & neuter -о: zero ending — кни́га → книг, окно́ → о́кон.

That zero ending often forces a helper vowel to break up the final consonant cluster — a fleeting vowel: окно́ → о́кон, су́мка → су́мок, де́вушка → де́вушек. Learn these forms individually — they are the trickiest part of the whole declension system.

Moving stress

Endings are only half the battle: the stress can jump between the stem and the ending as a noun declines, and it is not always predictable. Learn the stress together with the word:

• стол → стола́ (table → of the table) — stress moves onto the ending
• о́зеро → озёра (lake → lakes) — stress and the ё jump in the plural
• рука́ → ру́ки (hand → hands) — stress moves back onto the stem in the plural

Because stress is a property of each individual word, dictionaries and this site always mark it. When you meet a new noun, note where the stress goes in a couple of forms, not just the nominative.

Indeclinable nouns

A small group of nouns — almost all borrowings — never change at all. They keep one form in every case and number:

• ко́фе (coffee), метро́ (metro), такси́ (taxi), пальто́ (coat), кино́ (cinema), меню́ (menu)

So you say Я пью ко́фе (I drink coffee), Я е́ду на метро́ (I am going by metro) and Я купи́л два пальто́ (I bought two coats) — the noun stays identical. The case still exists grammatically; it is just not shown on the word, so the words around it (adjectives, verbs) carry the meaning.

How this connects to the rest of grammar

Nouns do not decline in isolation. Every adjective and pronoun that describes a noun must agree with it — matching its gender, number and case. When стол becomes столо́м, an adjective in front of it changes too: но́вым столо́м (with a new table). That agreement is the subject of adjective declension. And since a noun's class is tied to its gender, it is worth being solid on noun gender first.

Common mistakes

• Writing -ы after к / г / х (or a hushing consonant). The 7-letter rule demands -и.
  кни́гы, де́вушкы (wrong) → кни́ги, де́вушки (correct)
• Forgetting that animate masculine accusative = genitive.
  Я ви́жу брат (wrong) → Я ви́жу бра́та (correct)
• Using the 1st-declension instrumental on a 3rd-declension noun. Soft-sign feminine nouns take -ью.
  но́чой (wrong) → но́чью (correct)
• Declining an indeclinable noun. Borrowings like ко́фе, метро́, пальто́ never change.
  в метре́, на такси́е (wrong) → в метро́, на такси́ (correct)
• Sorting a noun by meaning instead of its ending. па́па is masculine but declines like ма́ма (1st declension).

Summary

• Declension is a noun changing its ending across the six cases, in singular and plural.
• Almost every noun fits one of three classes, decided by gender and nominative ending.
• 1st: -а / -я nouns (ма́ма, неде́ля); 2nd: masculine consonant/-й and neuter -о / -е (стол, окно́); 3rd: feminine -ь (ночь).
• Hard and soft stems mirror each other: -а/-о/-ы/-у vs -я/-е/-и/-ю.
• Accusative of inanimate masc/neut = nominative; of animate masculine = genitive; feminine -а has its own -у.
• The genitive plural (столо́в, книг, о́кон, ноче́й) is the hardest ending; watch for fleeting vowels.
• Stress can move between stem and ending — learn it per word.
• Borrowings like ко́фе, метро́, такси́, пальто́ are indeclinable.