Learn Hardcore Russian: Маленькая река протекает рядом с домом.

Because in Russian adjectives must agree in gender, number, and case with the noun they modify. Here река is feminine, singular and in the nominative case (as the subject), so the adjective takes the ending -ая. A masculine nominative adjective would be маленький, and a neuter one would be маленькое.

Why is река in the nominative case?

The nominative case marks the subject of the sentence, which is the entity performing the action. Since река (“river”) is the subject that “flows,” it appears in the nominative.

What is the difference between протекать and течь, and why is протекает used here?

Both verbs mean “to flow,” but:
• течь is more general and common in everyday speech.
• протекать often emphasizes the location or the process of flowing along a path.
Here, протекает (imperfective, present tense) highlights the ongoing action of the river flowing next to the house.

Why is протекает in the present tense, and why isn’t there a perfective present form?

In Russian, imperfective verbs like протекать have present-tense forms to describe ongoing or habitual actions. Perfective verbs do not have a true present tense; using the “present” form of a perfective verb actually implies future. So to express a single, completed flow in the future, you’d say река протечёт (future perfective).

What does рядом с mean, and why is домом in the instrumental case?

рядом с means “next to” or “near.” Prepositions of proximity like рядом с require the instrumental case for the following noun. That’s why дом becomes домом (“house” → “by/near the house”).

Could we use мимо дома instead of рядом с домом?

Yes. мимо + genitive (дома) means “past” or “by” the house, focusing on the movement past it. So Маленькая река протекает мимо дома is also correct and idiomatic.

Why isn’t there any article before маленькая река, like “a” or “the”?

Russian does not use articles. There are no words corresponding to “a” or “the.” Definiteness or indefiniteness is understood from context, emphasis, or sometimes added with demonstratives like эта река (“this river”).

Can I move рядом с домом to the beginning of the sentence?

Yes. Russian allows flexible word order for emphasis or style. For example:
Рядом с домом протекает маленькая река.
This version highlights the location first and can sound more poetic or emphatic.