The Prepositional Case: Part 1

So, today we're talking about the prepositional case. The number of situations where this case may be used is limited, as you can guess from its name: we always use nouns in this case with prepositions. The most important are three of them: "o", "в" and "на" (though it's also used with the prepositions "при" and "по" - with the latter when it means "after').

As we were talking before, when you need a noun in one of the oblique cases, you have to change its ending. Which ending do we need in this case? 

First, we need to find out what is the gender and the number of the noun we use. Second, we need to take into account what the singular noun ends by in the nominative case. 

Most of words have the ending -e in the singular form of the prepositional case. They are: masculine nouns, which end by a hard or a soft consonant (except for ones ending by -ий); feminine nouns which end by -a and -я (except for ones ending by -ия); neuter nouns which end by -o, -e (except for ones ending by -иe). Masculine nouns which end by -ий, feminine ones which end by -ия and neuter ones which end by -ие in the nominative will have the ending -ии in the prepositional case. Feminine nouns ending by a soft consonant (i.e. the ones which have "ь" in the end) will have the ending -и in the prepositional case. 

The rule describing the plural nouns is actually much simpler. Here you need to consider just two cases. If the last consonant in a word (in the singular form, the nominative case) is hard, then you will have the ending -ах, if it's soft, then -ях (please, remember: consonants followed by "ь" or "и" are always soft).

There are, however, several exceptions (it wouldn't be Russian, if there were none :)). The following nouns have the ending -у in the prepositional case when they follow the prepositions "в", "на" (be careful: in the combination with the preposition "o" they still end by "e"): в шкафу, в лесу, в углу, в саду, в носу, в году, в порту, в аэропорту, в снегу, в дыму, в раю, на полу, на мосту, на берегу, на носу, на боку, на краю, на дому (in the phrase "работать на дому") and some other ones. If you'd like to check if a word has this form (it's called 'locative'), you may use Wiktionary: just find a word you're going to use and look if there is a form after the prepositional case form in the case table (it's marked with Russian "М.", which stands for "местный падеж", the locative).

You may also ask, in which cases we use these prepositions (the prepositions "в" and "на" are especially confusing, for it may seem hard to distinguish between the situations when you need the former one and the situations when you need the latter one). We we'll be talking about this next time. See you!