Перед сном я снимаю с собаки поводок и ошейник, а она сразу ложится у двери.

Because перед normally takes the instrumental case when it means before / in front of.

So:

• сон = sleep
• сном = instrumental singular of сон

That gives:

• перед сном = before sleep / before going to bed

This is a very common pattern:

• перед работой = before work
• перед ужином = before dinner
• перед встречей = before the meeting

So here перед сном means before going to bed.

Because the preposition с in the sense of from, off requires the genitive case.

Here the verb is снимать = to take off / remove, and the thing is being removed from the dog, so Russian uses:

• с собаки = off the dog / from the dog

Compare:

• снять шапку с ребёнка = take the hat off the child
• снять картину со стены = take the picture off the wall

So:

• собака = nominative
• собаки = genitive after с

Снимаю is the imperfective present-tense form of снимать.

In Russian, the present tense of an imperfective verb can describe:

• something happening now, or
• a habitual/repeated action

In this sentence, it most naturally sounds like a usual routine:

• Before bed, I take off the dog’s leash and collar...

If you used сниму, that would be perfective future:

• Перед сном я сниму... = Before bed, I will take off...

So снимаю fits a general habit or regular evening action.

They are two different dog-related objects:

• поводок = leash / lead
• ошейник = collar

So:

• снимаю с собаки поводок и ошейник = I take the leash and collar off the dog

A learner may notice that in real life the leash is usually taken off the collar, but Russian can still naturally say this as removing both items from the dog.

Because these words are the direct objects of снимаю.

The verb снимать takes the thing being removed as a direct object:

• снимаю поводок
• снимаю ошейник

In an affirmative sentence, direct objects of this type are usually in the accusative case. For masculine inanimate nouns like these, the accusative looks the same as the nominative:

• поводок → accusative поводок
• ошейник → accusative ошейник

So they look unchanged, but grammatically they are accusative.

Here а is a very common conjunction that often means something like:

• and meanwhile
• while
• and as for
• sometimes a mild but

It does not always mean a strong contrast.

In this sentence, а она links the dog’s reaction to the speaker’s action:

• I take off the leash and collar, and she immediately lies down by the door

Using а makes the transition feel natural and conversational, as if you are shifting attention from what I do to what she does.

If you said и она, it would sound more like simple addition. А она is often the more idiomatic choice in this kind of two-part sentence.

Because собака is grammatically feminine in Russian.

So even if the dog’s actual sex is unknown, Russian often refers back to собака with feminine forms:

• собака ... она

That is because agreement follows the grammatical gender of the noun.

If the speaker wanted to make it specifically masculine, they might use пёс instead:

• пёс ... он

But with собака, feminine agreement is normal.

This is an important difference.

• ложиться = to lie down / to go into a lying position
• лежать = to be lying / to be in a lying position

So:

• она сразу ложится у двери = she immediately lies down by the door
• она сразу лежит у двери would not work well here, because лежит describes the state, not the action of moving into that state

Russian often distinguishes:

• action of changing position: сесть, встать, лечь / ложиться
• resulting position: сидеть, стоять, лежать

So ложится is correct because the dog is starting to lie down.

Ложится is imperfective present, while ляжет is perfective future.

• ложится = lies down / is lying down / lies down habitually
• ляжет = will lie down once

Since the sentence sounds like a regular bedtime routine, Russian uses the imperfective:

• она сразу ложится = she immediately lies down

If you were describing one future occasion, you might say:

• она сразу ляжет у двери = she will immediately lie down by the door

So the choice again reflects the idea of habitual repeated action.

Here у means by / near / next to, and it takes the genitive case.

So:

• дверь = door
• двери = genitive singular

Thus:

• у двери = by the door / near the door

This is a very common construction:

• у окна = by the window
• у дома = by the house
• у кровати = by the bed

So the dog lies down near the door.

Yes. Возле двери is also possible and means near the door.

The difference is mostly stylistic:

• у двери = very common, compact, natural
• возле двери = also natural, a little more explicitly near/beside

In this sentence, у двери is perfectly idiomatic and probably the most neutral choice.

Сразу means:

• immediately
• right away
• at once

So:

• она сразу ложится у двери = she immediately lies down by the door

It shows that the dog does this as soon as the leash and collar are removed. It makes the action feel automatic and habitual.

The sentence has a very natural word order, but Russian word order is fairly flexible.

Neutral version:

• Перед сном я снимаю с собаки поводок и ошейник, а она сразу ложится у двери.

You could change things for emphasis, for example:

• Я перед сном снимаю с собаки поводок и ошейник...
• ...а у двери она ложится сразу.

But those alternatives change the focus or sound less neutral.

The original order is good because it flows naturally:

1. time setting: перед сном
2. speaker’s action: я снимаю...
3. dog’s reaction: а она сразу ложится...

Russian has no articles like the or a/an.

So nouns appear without a separate word for definiteness:

• с собаки = from the dog / off the dog
• у двери = by the door
• поводок и ошейник = the leash and collar / a leash and collar

English requires articles, but Russian usually leaves that information to context.

In this sentence, the context makes it clear that these are the specific dog’s leash, collar, and the relevant door, so English naturally uses the.

Yes. Literally, перед сном means before sleep, but in normal English translation it often corresponds to:

• before bed
• before going to sleep
• at bedtime

This is a very common and natural Russian expression. Russian often uses сон where English prefers bed in everyday routines.

So even though the literal wording is different, the phrase is completely normal.