Learn Hardcore Russian: Иногда он убегает куда‑то играть, и тётя зовёт его ужинать. - Sometimes he runs off somewhere to play, and my aunt calls him to dinner.

In Russian, an infinitive after a verb of motion often expresses purpose: убегает играть = “runs off to play.”
If you said он убегает и играет, it would mean “he runs away and plays” (two separate actions), not “runs away in order to play.”
So убегает играть is like English “runs away to play,” and играть must stay in the infinitive.

What exactly does убегает mean compared to just бегает or бежит?

бегает = “(he) runs” in general, habitually or back and forth.
бежит = “(he) is running” right now, in one direction.
убегает (from убегать) adds the prefix у-, which implies moving away / running off / escaping.

So он убегает is “he runs away / runs off (from here),” not just “he runs.”

Is убегает present or future? How does aspect work here?

Убегает is present tense, imperfective aspect. Here it describes a repeated / habitual action (“sometimes he runs off”).
The perfective partner is убежать; its “present” forms are used with future meaning:

он убегает = “he (typically) runs off / is running off.”
он убежит = “he will run off.”

Why is it куда‑то, not где‑то? What’s the difference?

Russian distinguishes location vs direction:

где = “where (at?)” (static location)
куда = “where (to?) / to what place?” (direction / movement toward)

Since убегает is motion to somewhere, you need куда‑то (“to somewhere”).
Где‑то would mean “somewhere (at some place),” without the idea of going there.

What does the ‑то in куда‑то do?

The ending ‑то makes an indefinite pronoun/adverb, similar to adding “‑ever” or “some‑” in English:

куда = where (to)?
куда‑то = to somewhere / to some place (unspecified).

It often implies “I don’t know / don’t care exactly where.”
Compare: кто‑то = “someone,” что‑то = “something,” где‑то = “somewhere (at).”

What case is тётя in, and why this form?

Тётя here is in the nominative singular; it’s the subject of the verb зовёт (“the aunt calls”).
Base form: тётя = “aunt” (feminine noun, 1st declension).
So тётя зовёт literally: “the aunt calls.”

Is тётя a diminutive? Does it sound childish?

Historically, тётя was a diminutive of тётка, but in modern Russian тётя is the normal everyday word for “aunt.”
It can also be used informally for an older woman (“that lady”), but in the sentence it simply means “his aunt” and does not sound childish.

Why is it зовёт его, not зовёт он or зовёт ему?

Звать кого? takes the accusative case (direct object):

он (nominative, subject) → его (accusative, object).

So тётя зовёт его = “the aunt calls him.”
Зовёт он would mean “it’s he who calls,” and ему is dative (“to him”), which doesn’t fit here.

Why is ужинать an infinitive here? Could you also say зовёт его на ужин?

Yes, both patterns exist:

звать кого + инфинитив: зовёт его ужинать = “(she) calls him to have dinner.”
звать кого на + Acc.: зовёт его на ужин = “(she) calls him to (for) dinner.”

With ужинать (verb) the focus is on the activity of having dinner;
with на ужин (noun), on the event/meal itself. Both are natural.

What’s the difference between ужинать (verb) and ужин (noun)?

ужин = dinner (the meal, a noun): У нас в шесть ужин – “We have dinner at six.”
ужинать = to have dinner / to dine (a verb): Мы ужинаем в шесть – “We have dinner at six.”

In the sentence, зовёт его ужинать = “calls him to have dinner.”

Can the word order change, like тётя его зовёт ужинать or его тётя зовёт ужинать?

Yes, Russian word order is quite flexible, and all of these are grammatically possible:

тётя зовёт его ужинать (neutral, straightforward).
тётя его зовёт ужинать (slightly more emphasis on его = it’s him she calls).
его тётя зовёт ужинать (emphasis on его тётя = his aunt is the one calling).

The basic roles (subject, object) are marked by endings/pronouns, not by position.

Why is there a comma before и in …играть, и тётя зовёт…?

In Russian, when и connects two independent clauses (each with its own subject and verb), you usually put a comma before и:

он убегает куда‑то играть,
и тётя зовёт его ужинать.

Each part could stand as a separate sentence, so they’re separated by a comma.

What does иногда do here, and where else can it go in the sentence?

Иногда means “sometimes” and is an adverb of frequency.
You can usually move it around without changing the core meaning:

Иногда он убегает куда‑то играть… (most natural).
Он иногда убегает куда‑то играть… (also common).

Placing иногда at the very beginning slightly emphasizes the “sometimes” part.

How are тётя, зовёт, and куда stressed and pronounced?

тётя: stress on ё – ТЁ‑тя; ё is always stressed, pronounced like “yo” in “yogurt.”
зовёт: stress on ё – за‑ВЁТ (approx. za‑VYOT).
куда: stress on the last а – ку‑ДА (ku‑DA).

Remember: in properly written Russian, ё always has stress, so тётя, зовёт are easy stress-wise.