A friend of mine has lived in Russia for about 8 years and speaks the language as a real pro. There is only one detail about Russian that still drives him bonkers. ‘I will only consider myself a near-native speaker when I come to grips with your perverse numeric declensions. Holy cow, couldn’t you just make it any more complicated?’
Indeed, grammatically, numerals in Russian are classified into cardinal, ordinal and collective, each group with its set of case endings and exceptions from rules.
Ordinal numbers, such as первый, второй, десятый (first, second, tenth), etc. act like adjectives and follow the same case endings, according to their grammatical gender.
первый like далёкий первого like далёкого первому like далёкому первый/первого like далёкий/далёкого первым like далёким первом like далёком
One exception is ‘третий’ (third) that follows the same pattern as possessive pronouns/adjectives:
мой like третий моего like третьего моему like третьему моего/мой like третьего/третий моим like третьим моём like третьем
Then there come complex ordinal numbers that you most frequently will use when talking about years. As opposed to English, where ‘1984’ is pronounced as ’nineteen eighty-four’, in Russian you actually have to say the entire number as it is, in every declension. Do no be frightened: only the ending of 1984 is an ordinal number, while the rest of it is a string of cardinal numbers that do not assume case endings.
Родился в тысяча девятьсот восемьдесят четвёртом году. – Born in 1984 (ablative case)
So, instead of saying ‘in nineteen eighty-four’, in Russian you say «в тысяча девятьсот восемьдесят четвертом году».
As for cardinal numbers, prepare to get yourself into a maze:
один (1) follows the same endings as ordinal numbers.
два (2), три (3), четыре (4) follow their own special declension. двух двум два/двух двумя двух
Numbers 5 to 30 follow the case endings of female gender nouns with zero ending.
пять лошадь пяти лошади пяти лошади пять лошадь пятью лошадью пяти лошади
100, 40 and 90 only have two forms, nominative case and all other cases (ending with -a).
When it comes to complex numerals, all parts of them have to assume case endings according to the rules listed above! So you better not talk about 2 458 cats in Russian because it will sound like:
У меня есть две тысячи четыреста пятьдесят восемь кошек! – I have 2 458 cats (and I am a fully functioning cat lady). У меня нет двух тысяч_ четырёхсот пятидесяти восьми кошек! – I do not have 2 458 cats (requires genitive case). All the parts assume their own endings: two, thousand, four, hundred, fifty and eight.
Now that you are sliding into silent desperation, may you be consoled by the fact that nobody ever writes these numbers in words, and even native speakers mess up the endings all the time. There are still a lot of exceptions to the rules and odd letters sneaked in and out there, but the more you speak the more patterns settle down in your head.
Article by Anna Rudycheva