Learn Hardcore Polish: Pralka jest cicha, więc dzieci śpią. - The washing machine is quiet, so the children are sleeping.

Because adjectives agree with the noun’s gender and number. Pralka is feminine singular, so the adjective must be feminine singular nominative: cicha.

Masculine: cichy
Feminine: cicha
Neuter: ciche
Plural (masculine personal): cisi
Plural (non‑masculine‑personal): ciche

What cases are pralka and dzieci in?

Both are in the nominative case because they are subjects of their clauses:

Pralka (nominative singular) … jest cicha
Dzieci (nominative plural) … śpią The predicate adjective cicha is also nominative to agree with pralka.

Can I drop jest here and say Pralka cicha?

Not in standard, neutral Polish. In the present tense, the copula jest is normally required: Pralka jest cicha. Omitting it (e.g., Pralka cicha) sounds like a headline, note, or very telegraphic style.

Do I need a comma before więc?

Yes. Więc is a coordinating conjunction linking two finite clauses, so put a comma before it: Pralka jest cicha, więc dzieci śpią. You normally do not put a comma after więc.

Can I use bo or ponieważ instead of więc?

Yes, but they mean because (cause), not so/therefore (result). To keep the same meaning, flip the clauses:

Dzieci śpią, bo pralka jest cicha.
Dzieci śpią, ponieważ pralka jest cicha. Using więc expresses the result: Pralka jest cicha, więc dzieci śpią.

Why is it śpią and not something like są śpiące?

Polish uses the simple present to express English present continuous. Dzieci śpią = “The children are sleeping.”

Dzieci są śpiące usually means “The children are sleepy (drowsy),” not that they’re currently asleep.
As an adjective/participle, śpiące dzieci = “sleeping children,” but the predicate form for “are sleeping” is the verb śpią.

How do I pronounce the tricky parts: pralka, cicha, więc, dzieci, śpią?

pralka: PRAHL-kah (rolled r; both a’s like in “father”)
cicha: CHEE-kha (the ch is a guttural sound, like in Scottish “loch”)
więc: VYENTS (Polish w sounds like English v; ę before c sounds like “en”)
dzieci: JYET-chee (soft d+j sound at the start)
śpią: SH-PYON (soft sh; final ą is a nasal o, approximated as “on/own”)

What’s the difference between cicha, cicho, and cisza?

cicha = “quiet” as an adjective describing a feminine noun: Pralka jest cicha.
cicho = “quietly” (adverb) or “it is quiet” in impersonal phrases: Pralka chodzi cicho (The washer runs quietly). Jest cicho (It is quiet).
cisza = “silence” (noun): W domu jest cisza. Don’t say Pralka jest cicho when you mean the machine itself is quiet; use cicha.

What exactly is dzieci? What’s the singular? How does agreement work?

The singular is dziecko (child). The plural is irregular: dzieci (children). It’s a non‑masculine‑personal plural, so:

Adjectives: małe dzieci (not mali)
Past-tense verb agreement: Dzieci spały (not spali) Present-tense verbs don’t show gender, so dzieci śpią is just 3rd person plural.

Does Polish distinguish between “sleep” and “are sleeping” in the present?

Usually no. The simple present covers both habitual and ongoing actions. Dzieci śpią can mean “The children sleep (habitually)” or “The children are sleeping (right now).” Context (here, więc) tells you it’s a current result.

Could I start the sentence with Więc?

Yes, in context you can say Więc dzieci śpią. That’s often used as a discourse connector meaning “So, the children are sleeping.” The neutral full sentence here is Pralka jest cicha, więc dzieci śpią.

Polish has no articles. How do I say “this washing machine” or make it clearly definite?

Use a demonstrative. For “this”: Ta pralka jest cicha.
Without a demonstrative, pralka can be read as “a/the washing machine,” decided by context.

Is there a more natural way to say a machine “runs quietly”?

A very idiomatic option is Pralka chodzi cicho (“The washing machine runs quietly”). You can keep the original clause as is, or swap to this phrasing depending on the nuance you want.

Can I use żeby for “so (that)” here?

That changes the meaning from result to purpose. Żeby introduces purpose:

Pralka jest cicha, żeby dzieci mogły spać. = “The washing machine is quiet so that the children can sleep.” (intended purpose) Your original with więc states a result, not an intention.