Learn Hardcore Russian: Потом он возвращается откуда‑то с улыбающимся лицом. - Then he returns from somewhere with a smiling face.

возвращать = to return (something), to give back
- Я возвращаю книгу. – I return the book.
возвращаться = to return, to come back (oneself)
- Он возвращается. – He returns / he comes back.

So возвращается literally is “(he) returns himself,” which in Russian is just the normal way to say “he comes back.”
You use возвращаться (with -ся) when the subject is coming back, not returning an object to someone.

Why is it возвращается (present tense) and not past like вернулся if it’s part of a story?

Russian often uses the “historical present” in narration, just like English:

Потом он возвращается откуда‑то…
Then he comes back from somewhere…

This present tense can describe past events to make them feel vivid and immediate. In more neutral narration of finished past events, you would expect:

Потом он вернулся откуда‑то… – Then he came back from somewhere.

So:

возвращается – present/imperfective, used here as “historical present” or to describe a repeated/typical sequence.
вернулся – past/perfective, a single completed return.

What’s the difference between возвращаться and вернуться?

They are an aspect pair:

возвращаться – imperfective
- focuses on process, repetition, or general fact
- tenses: past, present, future (compound)
- Он всегда возвращается поздно. – He always comes back late.
вернуться – perfective
- focuses on a single completed event
- tenses: past, future (simple), no present
- Он вернулся поздно. – He came back late (once, finished).
- Он вернётся завтра. – He will come back tomorrow.

In the sentence Потом он возвращается…, the imperfective fits a “step in a sequence” style, especially in a story told in the historical present.

What exactly does откуда‑то mean? How is it different from just откуда?

откуда by itself is usually a question word: from where?
- Откуда он возвращается? – Where is he coming back from?
откуда‑то adds the suffix ‑то, which makes it indefinite:
- откуда‑то ≈ from somewhere (I don’t know / don’t specify from where)

So:

Он возвращается откуда‑то… – He is coming back from somewhere (unspecified place).

The ‑то suffix can be attached to many question words to make them indefinite:

кто‑то – someone
где‑то – somewhere
когда‑то – sometime

What’s the difference between откуда‑то, где‑то, and куда‑то?

They all have ‑то (“some…”) but refer to different directions:

где‑то – somewhere (location, “where?”)
- Он где‑то там. – He is somewhere over there.
куда‑то – to somewhere (direction “to where?”)
- Он ушёл куда‑то. – He went off somewhere.
откуда‑то – from somewhere (direction “from where?”)
- Он возвращается откуда‑то. – He’s coming back from somewhere.

So in your sentence, откуда‑то is correct because возвращаться implies movement from a place.

What does the little dash in откуда‑то do? Is it a hyphen, and why is it there?

Yes, it’s a hyphen. In Russian, the indefinite suffix ‑то is always written with a hyphen after pronouns and question words:

кто‑то – someone
что‑то – something
где‑то – somewhere
откуда‑то – from somewhere
когда‑то – sometime

There is no space before or after the hyphen.
It’s purely an orthographic rule; it doesn’t change pronunciation, just shows that ‑то is attached as an indefinite marker.

What does с mean in с улыбающимся лицом? Is it “with” or “from”?

Here, с means “with” in the sense of “accompanied by” or “having”:

с улыбающимся лицом – with a smiling face

Russian с + instrumental case often expresses “with (having this feature / accompanied by)”:

Он пришёл с другом. – He came with a friend.
Она стояла с закрытыми глазами. – She stood with (her) eyes closed.

So in this sentence с does not mean “from” (that would usually be из, от or с + genitive, depending on the noun), but simply with.

Why is it улыбающимся лицом? What form is улыбающимся and why is лицом in that case?

улыбающимся лицом is in the instrumental case because of с (= “with”):

лицо – face (neuter noun)
- Nominative: лицо
- Instrumental singular: лицом
улыбающийся is a present active participle of улыбаться (to smile):
- base: улыбаться → participle: улыбающийся = smiling
- It behaves like an adjective and must agree with the noun:
  - gender: neuter (because лицо is neuter)
  - number: singular
  - case: instrumental (to match лицом)
So neuter instrumental: улыбающимся.

Together:

с улыбающимся лицом = “with a smiling face,” literally “with [a] face that is smiling,” and both words (улыбающимся, лицом) are in the instrumental singular.

Could we say он улыбается, instead of он возвращается с улыбающимся лицом? What’s the difference?

They’re close in meaning, but not identical in focus.

Он возвращается, улыбается. – He returns, he is smiling.
Focus is on the action of smiling.
Он возвращается с улыбающимся лицом. – He returns with a smiling face.
Focus is on his appearance / expression as a state at the moment of return.

Other natural variants:

Он возвращается, улыбаясь. – He returns, smiling. (gerund, emphasizes the process)
Он возвращается с улыбкой. – He returns with a smile. (emphasizes the smile as an object/feature)

С улыбающимся лицом sounds more descriptive, almost like a narrative detail about how he looks.

What exactly is улыбающимся grammatically? Is it an adjective or a verb?

улыбающимся is a participle (specifically, a present active participle of the imperfective verb улыбаться).

Verb: улыбаться – to smile
Participle: улыбающийся – smiling (the one who smiles)

Participle properties:

Formed from a verb → keeps a verbal meaning (doing something).
Declines like an adjective → agrees in gender, number, case:
- Nom. neuter sg: улыбающееся лицо
- Instr. neuter sg: улыбающимся лицом

So you can think of it as something between a verb and an adjective: “a face that is smiling” → a smiling face.

Could I say с улыбкой instead of с улыбающимся лицом? Is there a nuance difference?

Yes, с улыбкой is completely natural and often more common:

Он возвращается с улыбкой. – He returns with a smile.

Nuance:

с улыбкой – highlights the smile itself as an object/feature.
с улыбающимся лицом – more literary/descriptive, highlights the overall facial expression as a state.

In everyday speech, с улыбкой is shorter and a bit more neutral; с улыбающимся лицом sounds a little more detailed or stylistically “written.”

What does Потом mean here? Is it the same as “then”?

Потом means “then / afterwards / after that” in a temporal sense.

Сначала он уходит. Потом он возвращается.
First he leaves. Then he comes back.

Similar words:

затем – then, afterwards (a bit more formal/written)
после этого – after that (more explicit)

In this sentence, Потом simply marks the next step in the sequence of events.

How is the sentence pronounced, and where are the stresses?

Stresses (capitalized vowels show stress):

ПотОм – pa-TOM
он – on
возвращАется – vaz-vra-SHAE-et-sya
откУда‑то – at-KOO-da-to
с улыбаЮщимся – s oo-ly-ba-YÓO-shchims-ya
лицОм – lee-Tsom

Full phrase (roughly):
ПотОм он возвращАется откУда‑то с улыбаЮщимся лицОм.

So the main stress positions are: потОм, возвращАется, откУда‑то, улыбаЮщимся, лицОм.