Learn Hardcore Russian: Я снял свитер в комнате, а потом снова повесил его в прихожей. - I took off my sweater in the room, and then hung it back in the entryway.

снять (снял) = to take off / remove (here: to take off a sweater, i.e., remove it from your body)
повесить (повесил) = to hang up (complete the action of hanging it on a hook/hanger)

So the sentence narrates two finished, one-time actions in sequence.

Why is the speaker Я (I) included—can it be omitted?

Yes, Я is often optional because the verb form снял / повесил already tells you it’s “I” (masculine singular past). You could say:

Снял свитер в комнате, а потом снова повесил его в прихожей. Including Я can add emphasis or clarity (e.g., contrasting with someone else).

What does а потом mean, and how is а different from и?

потом = then / afterwards
а is a conjunction often meaning and/but with a mild contrast or shift in the story (like “and then” with a change of scene or action).

So а потом is very natural for narrative sequencing: “…and then…”, often implying “next” or “after that,” sometimes with a slight contrast.

Why is снова placed before повесил? Could it go elsewhere?

снова = again. Placing it before the verb is a common neutral position:

а потом снова повесил его… = “and then hung it up again…”

Other placements are possible but change emphasis:

а потом повесил его снова… (more emphasis on “again” as an afterthought)
а потом снова его повесил… (emphasis on его, less common unless contrasting objects)

Why is it повесил его—why use его, and what case is it?

его is the third-person masculine/neuter singular object pronoun: him/it. Here it means it (the sweater). It’s in the accusative role (direct object) after повесил.

Using его avoids repeating свитер:

…повесил свитер… is fine but sounds more repetitive.

Could you say повесил свитер without его? Which is more natural?

Yes, you can:

…а потом снова повесил свитер в прихожей.

Both are correct. его is often more natural in connected speech because the object is already known. Repeating the noun can sound slightly heavier, though it’s not wrong.

Why is it в комнате and в прихожей—what case are these?

Both are prepositional case after в when it means “in” (location):

комната → в комнате
прихожая → в прихожей

They answer “Where?”:

Where did I take it off? In the room.
Where did I hang it up? In the hallway/entryway.

How do I know в комнате means “in the room” and not “into the room”?

With в, Russian distinguishes:

location (Where?) → в + prepositional: в комнате
direction (Where to?) → в + accusative: в комнату

So в комнате must mean “in the room,” not “into the room.”

What’s the difference between снять свитер and снять свитер с вешалки?

снять can mean “remove” in different contexts:

снять свитер = take the sweater off your body (most likely here)
снять свитер с вешалки / с крючка = take the sweater down/off a hanger/hook

If you wanted to force the “took it down” meaning, you’d usually add the source: с вешалки, с крючка, etc.

Why is прихожая translated as “hallway”? What exactly is прихожая?

прихожая is specifically the entryway/foyer area inside an apartment/house near the front door—often where coats and shoes are kept. In English it can be “entryway,” “hall,” or sometimes “hallway,” depending on the home’s layout.

What would change if I used imperfective verbs: снимал / вешал?

Imperfective would shift the meaning away from single completed actions:

снимал could mean “was taking off / used to take off / took off (process-focused)” depending on context
вешал could mean “was hanging up / used to hang up”

Your original (снял… повесил) clearly tells a simple finished sequence: took it off, then hung it up.

Is the word order fixed? Could I rearrange parts of the sentence?

Russian word order is flexible, but changes emphasis. The original is neutral and clear:

Я снял свитер в комнате, а потом снова повесил его в прихожей.

Possible variations:

В комнате я снял свитер… (emphasizes “in the room”)
…и в прихожей снова повесил его. (emphasizes “in the entryway”)
Свитер я снял… (emphasizes “the sweater” as the topic/contrast)

The endings carry grammatical roles, so word order mainly affects focus and style.