Agreement of participles with nouns

In Russian, participles (причастия) function as attributes. They allow you to condense a relative clause (using который) into a single word. Active participles replace clauses where который is the subject, while passive participles replace clauses where it is the direct object. Participles only have Present and Past tense forms; they do not have a future tense. Furthermore, imperfective verbs can form both Present and Past tense participles, whereas perfective verbs only yield Past tense participles.

1. Active vs. Passive:
Participles are divided into active (the noun performs the action) and passive (the noun receives the action). Note that passive participles are generally formed from transitive verbs (verbs that take a direct object in the accusative case without a preposition). However, while transitivity is a general requirement, with only a few specific exceptions (like руководимый or управляемый), not all transitive verbs can form present passive participles. For example, many common imperfective verbs like писать, пить, есть, брать, and ждать lack this form. Because reflexive verbs (ending in -ся) are inherently intransitive, they can never form true passive participles. However, active participles with -ся are frequently used to express a passive meaning (e.g., дом, строящийся рабочими - the house being built by the workers). Passive participles also have short forms (краткие причастия) which function as predicates and do not decline by case, only by gender and number. These are overwhelmingly formed from the past tense of perfective verbs (e.g., письмо написано - the letter is written). When using passive participles, the agent (the 'doer' of the action) is expressed using the Instrumental case (e.g., книга, читаемая студентом - the book read by the student).

2. The Rule of Agreement:
Just like adjectives, full participles agree with the noun they modify. Participial phrases (with dependent words) can naturally precede or follow the noun, though their position affects punctuation. You must identify the noun's gender (masculine, feminine, neuter), number (singular, plural), and case (Nominative through Prepositional) and apply the corresponding ending to the participle. Crucially, because participles decline like adjectives, you must apply the animate accusative rule: if the modified noun is an animate direct object, the participle must take the Genitive ending. Warning: When condensing a который clause, the participle must take the case of the noun in the main clause, not the case of the который pronoun it replaces (e.g., Я вижу студента, который читает книгу - I see the student who is reading a book, becomes Я вижу студента, читающего книгу - I see the student reading a book, where the participle is in the accusative case and takes the genitive ending to match the animate noun студента).

3. Endings:
Participles use the same declension patterns as long-form adjectives (e.g., -ый, -ая, -ое, -ые). For example, if a verb is reflexive, like умываться, the participle will end in -ся (never -сь), regardless of the case ending (e.g., умывающийся мальчик - the washing boy).

4. Register and Usage:
This construction is common in formal, academic, and literary Russian. In casual speech, Russians often prefer using a который clause. However, becoming confident with agreement is essential for reading news, literature, and technical texts.

5. Punctuation:
When a participle is part of a phrase (a participial construction) and follows the noun, it must be set off by commas. If the participial phrase precedes the noun, commas are generally not used, though there are important exceptions: commas are required if the modified word is a personal pronoun (e.g., Уставший от волнения, я крепко заснул. - Exhausted from excitement, I fell fast asleep.), if the participial phrase carries an adverbial meaning (such as cause or concession), or if it is separated from the noun by other words.