Learn Hardcore Russian: Иногда в парке происходит что‑то интересное. - Sometimes something interesting happens in the park.

In this sentence, the meaning is “Sometimes something interesting happens *in the park”, so we talk about location, not movement.
Therefore we use the prepositional case: *в парке.

Why is парк changing to парке?

This is the prepositional case singular of a masculine noun ending in a consonant.

Nominative (dictionary form): парк (park)
Prepositional singular: в парке (in the park)

For most masculine nouns ending in a consonant, the prepositional singular adds -е:

стол → на столе (on the table)
город → в городе (in the city)
парк → в парке (in the park)

Why is there no word for “the” in в парке?

Russian has no articles (no a/an and no the).
The phrase в парке can mean:

in a park
in the park

Context decides whether the English translation needs a or the. In this sentence, English uses “the park” as the most natural choice, but Russian simply says в парке.

Why does the verb происходит come before что‑то интересное, when in English the subject usually comes before the verb?

Russian word order is much more flexible than English. The subject of this sentence is что‑то интересное (“something interesting”), and the verb происходит agrees with it (3rd person singular).

These versions are all grammatically correct:

Иногда в парке происходит что‑то интересное.
Иногда в парке что‑то интересное происходит.
Что‑то интересное иногда происходит в парке.

The chosen order “происходит что‑то интересное” slightly emphasizes the fact of something happening rather than what exactly it is. But the main point is: in Russian, the verb doesn’t have to follow the subject directly, as long as the form of the verb makes it clear.

Why is the verb происходит singular, not plural (происходят)?

The grammatical subject is что‑то (“something”), which is singular and neuter.
So the verb must be 3rd person singular:

что‑то происходит = something happens
много вещей происходят = many things happen (plural)

Even though “something interesting” could feel like “interesting things” in meaning, grammatically it is still one “something”, so the verb is singular: происходит.

What exactly is что‑то, and why is there a hyphen?

Что‑то literally is “what + -то”, and it means “something” in a vague, indefinite sense.

что = what
‑то = a particle that makes it indefinite (“some‑”)

In Russian, certain particles like ‑то, ‑нибудь, ‑либо attach to pronouns with a hyphen:

кто‑то = someone
что‑то = something
где‑то = somewhere
когда‑то = sometime / once

So the hyphen is standard spelling and is always required in forms like что‑то.

Why is it что‑то интересное and not что‑то интересный?

The adjective must agree with the grammatical gender, number, and case of the noun or pronoun it describes.

что‑то is grammatically neuter singular (like the pronoun что).
Therefore the adjective also takes the neuter singular form: интересное.

Compare:

интересный фильм (masculine)
интересная книга (feminine)
интересное место (neuter)
что‑то интересное (neuter, because of что)

What is the difference between происходит and случается or бывает in this kind of sentence?

All can be translated as “happens”, but they have different nuances:

происходит – neutral “takes place / happens”, often about events, situations
- Интересные вещи происходят. = Interesting things happen.
случается – “happens, occurs”, often with a nuance of by chance / occasionally
- Иногда в парке случается что‑то интересное. (Very close to the original, with a slightly more “by chance” feel.)
бывает – “there are times when / it happens that”, often about repeated, typical occurrences
- Иногда в парке бывает что‑то интересное. (More like: “Sometimes there is something interesting going on in the park.”)

Your original происходит is a neutral, common choice.

Can we say что‑нибудь интересное instead of что‑то интересное? What’s the difference?

Yes, you can say:

Иногда в парке происходит что‑нибудь интересное.

But there is a nuance:

что‑то = some specific but unknown thing (speaker assumes it exists).
– “Sometimes something interesting (in fact) happens…”
что‑нибудь = anything at all, often used in questions, suggestions, or when we don’t care what exactly.
– “Sometimes anything interesting happens…” (here it sounds a bit more vague, less specific).

In a neutral factual statement, что‑то интересное is more natural.

Why is there no comma after Иногда or after в парке?

Russian uses commas mainly to separate clauses and certain types of phrases, not simple adverbs and prepositional phrases.

Иногда (“sometimes”) is just an adverb.
в парке is a simple prepositional phrase.

They are not separate clauses, so no commas are needed.
The whole sentence is a single clause:

[Иногда] [в парке] [происходит] [что‑то интересное].

How does the present tense происходит work here? Is it present or “sometimes/usually” like English?

In Russian, the present tense of imperfective verbs is used both for:

Real present (happening now):
- Сейчас в парке происходит что‑то интересное.
  = Something interesting is happening in the park right now.
Habitual / repeated actions (like English “sometimes / usually / often do”):
- Иногда в парке происходит что‑то интересное.
  = Sometimes something interesting happens in the park.

So here, происходит is present imperfective used with Иногда, so it conveys a repeated, occasional action, similar to English simple present.

How is что pronounced in real speech? I often hear it like “што”.

In standard Russian pronunciation:

The word что is normally pronounced “што”: /што/.

Spelling stays что, but everyday pronunciation changes ч to ш in this very common word.
So your sentence would typically sound like:

Иногда в парке происходит што‑то интересное.

(Though in very careful, slow speech, some people may pronounce the full ч.)