Learn Hardcore Polish: Głośna muzyka rozprasza dzieci w bibliotece. - Loud music distracts children in the library.

Because muzyka is a feminine singular noun in the nominative case, and in Polish adjectives agree with the noun’s gender, number, and case. Feminine singular adjectives in the nominative end in -a (e.g., głośna muzyka, cicha muzyka, dobra książka).

What case is dzieci in, and why doesn’t it change in the plural?

Here dzieci is the direct object of rozprasza, so it’s in the accusative case. For dziecko (“child”), the nominative and accusative plural are identical: dzieci. That’s why you see dzieci for both “children” (subject) and “children” (object) in plural.

Why is it w bibliotece and not w bibliotekę?

The preposition w meaning “in” takes the locative case when expressing location (static “in”). The locative singular of biblioteka is bibliotece. If you wanted to express motion “into the library,” you’d use do biblioteki (genitive) or w + accusative (“wchodzić w bibliotekę”), but here we only state where the distraction happens.

How do you pronounce the ł in głośna, and where is the stress?

The letter ł is pronounced like English w, so głośna sounds roughly like “gwosh-na.” Polish stress almost always falls on the penultimate (second-to-last) syllable, so you say GŁOŚ-na.

What form of the verb is rozprasza, and what’s its infinitive and aspect?

rozprasza is the 3rd person singular, present tense form of the imperfective verb rozpraszać (“to distract”). Its perfective counterpart is rozproszyć (“to distract” with emphasis on the completion of the action).

Can I use przeszkadzać instead of rozpraszać here? What’s the difference?

Both involve disturbance but differ slightly:
• rozpraszać = to distract, to divert attention (kids lose focus).
• przeszkadzać = to bother or interfere (something annoys or obstructs).
So “głośna muzyka rozprasza dzieci” means it draws their attention away, whereas “głośna muzyka przeszkadza dzieciom” means it simply disturbs or annoys them (note dzieciom in dative with przeszkadzać).

Is the word order fixed? Could I say Dzieci w bibliotece rozprasza głośna muzyka?

Polish has relatively free word order, so you can rearrange elements for emphasis or style. However, the neutral order is Subject–Verb–Object–Adverbial: Głośna muzyka rozprasza dzieci w bibliotece. Your alternative is grammatically correct but might sound more poetic or emphatic.