Breakdown of В коридоре маленькая лампа включается, когда кто‑то проходит мимо датчика.
Questions & Answers about В коридоре маленькая лампа включается, когда кто‑то проходит мимо датчика.
Russian word order is flexible and is often used to show what is being emphasized.
В коридоре маленькая лампа включается…
Literally: In the corridor a small lamp switches on…
This structure puts в коридоре at the beginning, so the place is the starting point of the message. It sounds like the speaker is setting the scene: as for the corridor… there’s a small lamp that comes on…You could also say:
Маленькая лампа в коридоре включается…
Now the starting point is маленькая лампа; the corridor is just extra information about where it is.
Both are grammatically correct. The given word order slightly emphasizes the location (in the corridor) rather than the lamp itself.
The preposition в can take either the accusative or the prepositional case, depending on the meaning:
в + accusative = movement into a place
- Я иду в коридор. – I am going into the corridor.
в + prepositional = location in/inside a place
- Я в коридоре. – I am in the corridor.
In the sentence В коридоре маленькая лампа включается…, we are talking about where the lamp is located (in the corridor), not about movement into the corridor.
So коридоре is in the prepositional case after в.
In Russian, adjectives must agree with the noun in:
- gender (masculine / feminine / neuter),
- number (singular / plural),
- case.
Here:
- лампа is a feminine noun:
- Ends in -а (a common sign of feminine gender).
- маленькая is the feminine singular nominative form of the adjective маленький (small).
So:
- masculine nominative: маленький стол
- feminine nominative: маленькая лампа
- neuter nominative: маленькое окно
In the sentence, маленькая лампа is the subject, so it’s in the nominative case, and both words show feminine singular nominative endings.
The ending -ся (or -сь after vowels) makes a verb reflexive or middle voice, often meaning that the action happens by itself or that the subject is both doer and receiver.
включать / включить = to switch on (something)
- Он включает лампу. – He switches on the lamp.
включаться / включиться = to switch on / turn on (by itself)
- Лампа включается. – The lamp switches on / turns on (itself).
In our sentence, лампа включается suggests an automatic action (because of the sensor), not that a person actively switches it on. Using включает here would require a subject (someone who switches it on) and would change the meaning:
- Он включает лампу, когда кто-то проходит мимо датчика.
He turns on the lamp when someone walks past the sensor.
Russian uses the present tense with imperfective verbs to describe:
- regular, repeated actions,
- general rules or typical behavior,
- things that “always” or “usually” happen.
So:
- Лифт приезжает через минуту. – The elevator arrives in a minute. (regular behavior)
- Зимой рано темнеет. – In winter it gets dark early. (general fact)
Similarly:
- Лампа включается, когда кто-то проходит мимо датчика.
Means: The lamp (habitually / always) turns on when someone walks past the sensor.
This is the normal way to express such “whenever X happens, Y happens” rules in Russian.
In Russian, когда introduces a subordinate (dependent) clause of time, similar to when in English.
The structure is:
- Main clause: (В коридоре) маленькая лампа включается
- Subordinate clause: когда кто-то проходит мимо датчика
Russian punctuation rules require a comma before conjunctions like когда, потому что, если, что when they introduce a subordinate clause:
- Я позвоню, когда приду домой.
- Он ушёл, потому что устал.
So the comma before когда is obligatory here.
кто‑то is an indefinite pronoun meaning someone.
- кто = who
- кто‑то = someone (specific but unidentified person)
- кто‑нибудь = anyone (more “any random person” / in questions, etc.)
The hyphen is always written in such pronouns:
- кто‑то, что‑то, где‑то, когда‑то
Although кто‑то can refer to any person and could feel plural in meaning (“people in general”), grammatically it is 3rd person singular, so the verb is singular:
- кто‑то проходит
- кто‑то пришёл
You cannot say кто‑то проходят – that would be ungrammatical.
мимо is a preposition meaning past / by / alongside and it always takes the genitive case.
- мимо
- genitive:
- мимо дома – past the house
- мимо школы – past the school
- мимо окна – past the window
- genitive:
In the sentence:
- датчик is the base noun: sensor.
- The genitive singular form is датчика.
So мимо датчика = past the sensor / by the sensor.
That’s why you see датчика, not датчик.
The verb проходить means to pass / to go by / to walk through, and it usually needs a preposition to show what you are passing:
Common combinations:
- проходить мимо чего‑то – to pass by something
- проходить через что‑то – to go through something
- проходить по улице – to walk along the street
So:
- кто‑то проходит мимо датчика – someone walks past the sensor.
- Saying проходит датчик by itself would sound like the sensor is the thing being “gone through” physically, which is not what you mean.
Here, мимо датчика is an adverbial phrase indicating direction relative to the sensor.
Yes, если is grammatically possible, but there is a nuance:
- когда = when / whenever (temporal: at the time that X happens)
Implies that whenever someone passes, this is what happens. - если = if (conditional: on condition that X happens)
Slightly more “logical condition,” less “time-based” in feeling.
In practice, in such “automation” descriptions both are often acceptable:
…лампа включается, когда кто‑то проходит мимо датчика.
Focus on the time: at the moment someone passes, the lamp comes on.…лампа включается, если кто‑то проходит мимо датчика.
Focus on the condition: the lamp comes on if (under the condition that) someone passes.
The difference is subtle, like English when vs if; когда sounds a bit more like a description of a regularly observed behavior.
Both verbs can be used with lights, but they focus on different aspects:
включаться / включиться
Literally: to be switched on (electrically).
Focus: the act of switching on power or the device.- Лампа включается автоматически. – The lamp switches on automatically.
загораться / загореться
Literally: to start burning / begin to glow.
With lights, it often refers to the light beginning to shine, sometimes a bit more visual / poetic.- Огни загораются в темноте. – Lights come on in the dark.
In a technical, sensor-based context like this, включается is the more typical choice, because it’s clearly about the device being turned on by a system.
Aspect and tense in Russian combine to express both time and type of action (ongoing vs completed).
- проходить (imperfective) – to be walking / to walk (in general, repeatedly, process).
- пройти (perfective) – to walk past once, to complete the action.
Our sentence describes a general rule that can happen many times, not one specific future event. That’s why both verbs are imperfective present:
- лампа включается – the lamp (habitually) turns on,
- когда кто‑то проходит мимо датчика – when someone (habitually / whenever someone) passes by.
If you said:
- Лампа включится, когда кто‑то пройдёт мимо датчика.
this would describe one specific future event: The lamp will turn on when someone (once) walks past the sensor (on that particular occasion). That’s a different meaning.
The grammatical subject is маленькая лампа.
Breakdown:
- В коридоре – prepositional phrase (location: in the corridor).
- маленькая лампа – subject (a small lamp).
- включается – predicate verb (switches on).
- когда кто‑то проходит мимо датчика – subordinate clause of time.
So the core sentence is:
- Маленькая лампа включается.
В коридоре simply adds where this is happening; it is not part of the grammatical subject.