Learn Hardcore Russian: Между двумя домами протекает маленькая река. - A small river flows between the two houses.

The preposition между (between) always governs the instrumental case when indicating a position or movement between things. Thus два дома (two houses) becomes двумя домами in the instrumental plural.

How do cardinal numbers like два change when you use cases in Russian?

Cardinal numbers decline according to case. For example:

Nominative: два дома
Genitive: двух домов
Instrumental: двумя домами
In our sentence, we need the instrumental, so два → двумя, and дома → домами.

Why can’t we say между двух домов here?

Some prepositions take genitive (e.g. у, из), but между requires the instrumental. Genitive plural двух домов would be used with different prepositions, not with между.

Why is маленькая река in the nominative case?

Маленькая река is the grammatical subject performing the action “flows.” Subjects of verbs in Russian are in the nominative case. The adjective маленькая agrees with река in gender (feminine), number (singular), and case (nominative).

What is the tense and aspect of протекает, and why is it used here?

Протекает is the third person singular present tense of the imperfective verb протекать (“to flow through; to run along”). The imperfective aspect highlights an ongoing or habitual action—here, that the small river flows between the houses.

Could I use течёт instead of протекает, and is there a nuance?

Yes. Течёт is the present imperfective of течь (“to flow”).
• течь is more neutral or colloquial.
• протекать can emphasize the process or the route of the flow.
Both convey “the river is flowing between the houses.”

Is the word order fixed? Can I start with маленькая река?

Word order in Russian is flexible. You can say:
Маленькая река протекает между двумя домами.
Putting the subject first is the most neutral order; the original verb-first order slightly emphasizes the action or sets a scene.

What’s the difference between между and среди?

• между (“between”) is used for distinct, usually fewer items (often two, but can be more).
• среди (“among”) is used when something is within a group or mass of items without focusing on distinct separation.
Here, two houses are distinct, so между is correct.

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

Russian has no definite or indefinite articles. Whether you mean “a small river” or “the small river” is understood from context, without adding words.