Numbers in Russian: zero to a billion with stress, IPA and grammar

How Russian builds 11 to 99

The teens add -надцать to the unit: одиннадцать, двенадцать, тринадцать, and so on to девятнадцать. Wiktionary describes -надцать as the -teen suffix, and the forms are fully regular apart from small spelling adjustments: двенадцать uses the feminine две, and четырнадцать drops a vowel of четыре.

Twenty and thirty are two tens and three tens: двадцать and тридцать, from два and три plus -дцать. Fifty to eighty are built openly from the unit and десять: пятьдесят is literally five tens, a form Wiktionary explains as the old genitive plural of десять, required after numbers from five up. Compound numbers simply line up the parts without and: двадцать один is 21, сто сорок семь is 147.

Two numbers do not fit. Сорок, 40, comes from an Old East Slavic word for a bundle of forty sable pelts, a trade unit, and replaced the regular four tens. Девяносто, 90, appears from the twelfth century; its origin is unclear and it has no parallel outside East Slavic, where other Slavic languages say nine tens. Сто, 100, is a direct inheritance from Proto-Slavic *sъto.

One and two have genders

Один agrees with its noun like an adjective: один дом (one house), одна книга (one book), одно окно (one window). The same holds inside compounds: двадцать одна книга, twenty-one books, keeps the feminine singular.

Два has a feminine form две: два мальчика, two boys, but две книги, two books. Both examples are Wiktionary's. Three and four have no gender, and from пять upwards the numbers behave like nouns themselves, with their own case endings: с пятью мальчиками, with five boys.

Which case follows a number in Russian

This is the rule that makes numbers in Russian hard for learners. The last word of the number decides the case of the noun in the nominative and accusative. Один and all compounds ending in it (21, 31, 101) take the singular: один мальчик, двадцать один мальчик. Два, три and четыре and their compounds take the genitive singular: два мальчика, тридцать три мальчика. From пять to двадцать, and for every compound ending in 5 to 9 or 0, the noun takes the genitive plural: пять мальчиков, пятьдесят пять книг.

Wiktionary's usage notes state these patterns for один, два and пять, adding that in other cases the number and noun simply agree: с пятью мальчиками. The teens all follow пять, even одиннадцать, since only the final word counts and одиннадцать is one word.

Writing numbers: spaces, commas and zero

Russian groups thousands with a space and uses a comma as the decimal sign, the reverse of English habits: 1 234 567,89. The Unicode CLDR data for Russian defines exactly this, with a non-breaking space as the group separator, so software set to Russian prints numbers the same way.

Zero has two forms, ноль and нуль. Wiktionary traces ноль to German Null and ultimately to Latin nūllus; Wiktionary lists нуль as a second form with the same meaning, and both are masculine nouns that share one genitive, нуля.

Large numbers are nouns: тысяча is feminine, миллион and миллиард masculine, and they take the case after a number like any other noun: две тысячи, пять тысяч, три миллиона. Миллиард is the short-scale billion, 10⁹, a French loan that Russian uses where English says billion.

Common mistakes with numbers in Russian

A typical error is the plural after two, three or four: два мальчиков instead of два мальчика. The genitive singular after these numbers looks odd to English speakers, yet it is the standard form, and the compounds follow it: двадцать два мальчика.

The second is the gender of two. Две is required with feminine nouns, две книги, and the teen двенадцать keeps that feminine stem whatever the noun. Third, stress: пятьдеся́т and шестьдеся́т are stressed at the end, се́мьдесят and во́семьдесят at the start. Spelling adds one more trap among the numbers in Russian: the soft sign sits in the middle of пятьдесят and шестьдесят, but at the end of пять and шесть.