Learn Hardcore Russian: Моя подруга смотрела фильм, который был очень забавным. - My friend female watched a movie that was very funny.

The verb смотрела is in the feminine singular past tense. It agrees with the subject подруга, which is a feminine noun. In Russian, past tense verbs must match the gender and number of their subject, so because “подруга” is feminine, смотрела is used.

How does the relative clause “который был очень забавным” function in this sentence?

The relative clause “который был очень забавным” provides additional information about the noun фильм. It describes the film by specifying that it was very funny. The pronoun который refers back to фильм and must agree with it in gender and number, which is why it appears in the masculine singular form.

Why is the adjective забавным in the instrumental case?

In Russian, when using a linking verb like был (was), predicate adjectives typically appear in the instrumental case to indicate a state or quality. Here, забавным in the instrumental case tells us what state or quality the film possessed—it was very funny.

How is the relative pronoun который declined, and why does it take that form?

The pronoun который is declined in the masculine singular form because its antecedent, фильм, is a masculine singular noun. In this sentence, который is used in the role of the subject within the relative clause (был очень забавным), which is why it appears in its nominative form.

Why is there a comma before the relative clause “который был очень забавным”?

Russian punctuation rules generally require that subordinate clauses—such as relative clauses providing extra description—be set off from the main clause by a comma. Here, the comma separates the main clause (Моя подруга смотрела фильм) from the relative clause that gives additional information about the film.