Suppose you want to talk about someone, but either you do not know his name, or it would mean nothing to your listeners. In such a case you would tell them something about him which would help them to understand who he is. For example:
I am looking for the man who stole my car.
The underlined portion explains the word “man”. Without it the meaning would be less clear, but the sentence would still be grammatically complete:
I am looking for the man.
And the underlined portion is a complete sentence too:
Who stole my car. (In other words, “He stole my car.”)
Because in the combined sentence “who” comes right after “man” it is understood that they refer to the same person. We can use this same construction in Russian, only instead of the Russian word for “who” we use the special pronoun “который”:
Я ищу человека который украл мою машину.
The pronoun “который” always refers to the same thing as the noun which comes before it. Though который is a pronoun, it is declined as if it were an adjective. Refer to Grammar 5--Case Charts under Adjectives.
Here are the steps for building a correct and understandable sentence using который.
1) Note the gender and number of the noun which requires explanation:
Я ищу человека.
I am looking for the man.
In this case it is masculine singular. There is no need to note the case.
2) Find the noun in the second sentence which refers to the same person or thing and move it to the front if it is not there already:
Я сфотографировал его вчера.
|becomes||Его я сфотографировал вчера.|
I photographed him yesterday.
|Him I photographed yesterday.|
3) Replace the noun at the front with the proper form of “который”. Use the gender and number which you noted in step one, but use the case of the word it replaces. Here that case is animate accusative:
|Его я сфотографировал вчера.||becomes||Которого я сфотографировал вчера.|
|Him I photographed yesterday.||Whom I photographed yesterday.|
4) Insert (or in this case simply append) the explanatory sentence:
Я ищу человека, которого я сфотографировал вчера.
I am looking for the man whom I photographed yesterday.
In these examples the explanatory part is underlined.
|Я вижу книгу, которая упала.||I see the book which fell.|
|Я помогу человеку, который упал.||I will help the person who fell.|
|Упал человек, которому вы помогли.||The man fell whom you helped.|
|Выброси коробку, в котором болты пришли.||Throw away the box in which the bolts came.|
|Отправляй письмо, которые лежат на столе.||Send the letters which lie on the table.|
|Найдите даму, с которой Вы пришли.||Find the lady with whom you came.|
|Я не понимаю людей, которые не любят борщ.||I don't understand people who don't like borsch.|
|Нужен нам человек, который помог бы нам.||We need a man who would help us.|
|Дождь, который выпал вчера замёрз.||The rain which fell yesterday froze.|
Note: который can sometimes also be used as a question word, but that is beyond the scope of this article.