In Russian, numbers are not fixed labels. Like nouns, they change their endings for case: “with two friends” is с двумя́ друзья́ми, “in five cities” is в пяти́ города́х. Native speakers do this without thinking; this guide lays out every form so you can too.
B1–C113 min read6 × 6full case tables
Outside the nominative and accusative, the number and the noun stand in the same case, and the noun goes plural.
The short answer
A case is the ending a word takes for its role in the sentence. In the nominative and accusative (subject and object), numbers keep their basic form and control the noun: пять столо́в. In the other four cases, the number itself changes and the noun simply matches it in the plural: о пяти́ стола́х. In long numbers, every part changes.
1 · The key idea
Two zones: the number leads, or the number follows
Nominative · Accusative: the number leadsThe number keeps its basic form and decides the noun: 2–4 take genitive singular, 5+ take genitive plural.
Every other case: the number followsBoth the number and the noun take the case needed, and the noun is plural, whatever the number.
2 · One
оди́н behaves like an adjective
оди́н has a masculine, feminine and neuter form, like э́тот (this), and matches its noun in gender and case. The noun stays singular.
Case
Masculine
Feminine
Neuter
Nominative
Genitive
Dative
Accusative
Instrumental
Prepositional
In the accusative, the masculine form is одного́ for people and animals, оди́н for things: Я ви́жу одного́ челове́ка (ya VEE-zhu ad-na-VO chi-la-VYE-ka; Я = I, ви́жу = see, одного́ = one, челове́ка = person) but Я ви́жу оди́н дом (ya VEE-zhu a-DEEN dom; оди́н = one, дом = house).
3 · Two, three, four
два, три, четы́ре: one shared pattern
These three share endings: -х in the genitive and prepositional, -м in the dative, -мя in the instrumental. два has a feminine form, две, but only in the nominative and accusative.
Case
2
3
4
Nominative
Genitive
Dative
Accusative
Instrumental
Prepositional
4 · Five to thirty
пять to три́дцать: just like the noun дверь
Every number from 5 to 20, plus 30, ends in -ь and changes exactly like a feminine noun such as дверь (door): -и in three cases, -ью in the instrumental. The stress usually moves to the ending.
Case
5
8
20
Nominative
Genitive
Dative
Accusative
Instrumental
Prepositional
во́семь loses its е (a fleeting vowel) in every form except the basic one, and has two instrumentals: восемью́ (vo-sim’-YU) and the more common восьмью́ (vas’-MYU).
5 · The odd three
со́рок, девяно́сто, сто: only two forms each
Forty, ninety and a hundred are the easiest of all. Each has its basic form, and one other form for every remaining case.
40
90
100
6 · Hundreds and long numbers
Every part changes: с двадцатью́ пятью́ рубля́ми
Hundreds are two numbers glued together, and both halves change: две́сти → двухсо́т (of two hundred). In a long number, every word changes into the same case. In everyday speech Russians often simplify, but in writing and formal speech the full forms are expected.
Case
200
300
500
Nominative
Genitive
Dative
Accusative
Instrumental
Prepositional
ты́сяча (thousand) changes like the noun кни́га, and миллио́н like стол. They are nouns, so after them the counted thing is always in the genitive plural: с ты́сячей рубле́й (s TY-si-chey rub-LYEY; с = with, ты́сячей = a thousand, рубле́й = roubles).
7 · Both, and one and a half
о́ба / о́бе and полтора́
о́ба / о́беBoth. о́ба for masculine and neuter, о́бе for feminine. Unlike два, the two forms stay different in every case.
полтора́One and a half. It works like два: полтора́ часа́ (an hour and a half). In every other case it becomes полу́тора.