Learn Hardcore Russian: В парке запрещено бросать мусор. - It is forbidden to throw trash in the park.

This is an impersonal sentence: there is no grammatical subject. Запрещено is a short-form predicative (historically a short passive participle) used in neuter singular to state rules or general facts. The infinitive phrase бросать мусор functions as the content of what is forbidden, not as a grammatical subject. Similar patterns: Здесь запрещено курить. / Здесь разрешено фотографировать. / Здесь нельзя шуметь.

Can I say запрещается instead of запрещено?

Yes: В парке запрещается бросать мусор. Both mean “is prohibited.” Nuance:

запрещено sounds like a flat statement of rule/state (very common on signs).
запрещается feels a bit more formal/bureaucratic or procedural (“is prohibited by regulation”). Both are correct on signage and in official texts.

Could I replace it with нельзя?

Yes: В парке нельзя бросать мусор. Нельзя is a general impersonal “not allowed/one must not,” slightly more conversational than запрещено, but perfectly fine (also common on signs). Strength of prohibition feels similar; запрещено is a touch more formal.

Why is бросать imperfective here and not the perfective бросить?

General prohibitions take the imperfective to talk about actions in general (habitual/any occurrence). Using perfective (бросить) would sound odd, as if forbidding one single completed act. So: запрещено бросать/выбрасывать (imperfective) is the natural choice for rules.

Would verbs like выбрасывать, кидать, мусорить, or разбрасывать work here? What’s the difference?

бросать мусор: neutral “throw trash.”
выбрасывать мусор: “discard” (throw away), very common in rules/signs.
кидать мусор: more colloquial “to toss/throw trash.”
мусорить: intransitive “to litter” (no object). Very concise on signs: В парке запрещено мусорить. / Не мусорить!
разбрасывать мусор: “to scatter trash around,” emphasizes messiness.

All are possible; the most sign-like are выбрасывать мусор and мусорить.

What case is мусор in, and why not мусора?

It’s accusative singular (inanimate), which matches the nominative form: мусор. Transitive verbs like бросать take a direct object in the accusative. Мусора would be genitive and would not be used here. Note: under direct negation with не, Russian sometimes allows genitive (“genitive of negation”), e.g., не бросайте мусора, but with запрещено there’s no direct negation on the verb, so the normal accusative мусор is expected.

Why в парке and not в парк or на парке?

в парке (Prepositional) = location “in the park.”
в парк (Accusative) = motion “into the park.”
на парке is not idiomatic. If you want a more formal phrasing, you can say на территории парка (“on the territory of the park”), which is a set phrase with на.

Can I move в парке to a different position? Does word order matter here?

Yes. All of these are fine:

В парке запрещено бросать мусор. (location is the topic)
Запрещено бросать мусор в парке. (rule first, then location)
Бросать мусор в парке запрещено. (focus on the action) Meaning stays the same; differences are in emphasis/information structure, not grammar.

How would I address people directly (imperative) instead of stating a rule?

Use negative imperatives:

Polite plural/formal: Не бросайте мусор в парке, пожалуйста.
Shorter sign style: Не мусорите! or Мусор не бросать. (terse, very sign-like)

What’s a concise Russian equivalent of “No littering in the park”?

Common options:

В парке запрещено мусорить.
В парке нельзя мусорить.
Не мусорить! (if the sign is in the park)
Мусор не бросать.

How do I pronounce the sentence? Where are the stresses?

Stresses:

В па́рке (the preposition в often devoices to [f] before п: sounds like [f párkʲe])
запрещено́ (stress on the last syllable)
броса́ть
му́сор

One possible IPA: [f ˈparkʲe zɐprʲɪɕːɪˈno brɐˈsatʲ ˈmusər]

Why is it spelled with щ in запрещено? And where is the “yo” sound?

щ is a single letter pronounced as a long, soft “sh” [ɕː]. Don’t write шч here.
The form is запрещено́ (with е, not ё), stress on the final -но́. In the masculine short form you do see ё: запрещён. But the neuter short form is spelled with е: запрещено́.

Is запрещено present, past, or something else?

As a predicative, it’s essentially tenseless and states a general/current rule: “is forbidden.” If you need time reference, use auxiliaries:

Past: В парке было запрещено…
Future: В парке будет запрещено…

Can we specify who exactly is prohibited from doing it?

Yes, add a dative phrase:

В парке посетителям запрещено бросать мусор.
В парке детям нельзя мусорить. Dative marks the people affected by the rule.

Do we need any commas in this sentence?

No. It’s a simple impersonal clause with an infinitive phrase. No commas are required.

Should I add не somewhere? What happens if I do?

Do not add не unless you want to reverse the meaning.

В парке не запрещено бросать мусор = “It’s not forbidden to throw trash in the park” (i.e., it’s allowed).
Запрещено не бросать мусор = “It’s forbidden not to throw trash” (you must throw trash) — the opposite of what you want.

Is мусор countable? Can I use a plural?

Мусор is typically a mass noun and used in the singular. The plural мусоры exists only in specific technical meanings (types of garbage) and is not used for everyday “trash/litter.” If you want to name items, use countable nouns: окурки, бутылки, бумажки.

How would I ask “Is it allowed to throw trash in the park?” in Russian?

В парке можно бросать мусор?
More formal: В парке разрешено бросать мусор? or Разрешено ли в парке бросать мусор?