W nowym mieszkaniu stoi wysoki regał, a przy oknie wisi jasna firanka.

Because w meaning in takes the locative case when it answers where? rather than where to?

• w nowym mieszkaniu = in the new apartment → location, so locative
• w nowe mieszkanie would only make sense in a motion context with into, and even then Polish usually prefers different phrasing depending on the verb

Here the sentence describes where something is, so mieszkaniu is in the locative, and the adjective changes with it:

• nowe mieszkanie → nominative
• w nowym mieszkaniu → locative

Both words must match the locative singular form.

The base forms are:

• nowy = new
• mieszkanie = apartment / flat

After w in a location phrase, they change to locative:

• nowy → nowym
• mieszkanie → mieszkaniu

So:

• w nowym mieszkaniu = in the new apartment

This is normal adjective-noun agreement in Polish: the adjective always matches the noun in case, number, and gender.

Polish often prefers a more specific verb than just to be when describing the position of objects.

• stoi = is standing
• wisi = is hanging
• jest = is

So:

• stoi wysoki regał suggests a bookcase standing upright on the floor
• wisi jasna firanka suggests a curtain hanging by the window

Using jest would be more neutral and less vivid. Polish often sounds more natural with position verbs in descriptions like this.

Regał is the subject of the verb, so it stays in the nominative case.

In this sentence:

• regał stoi = the bookcase stands
• firanka wisi = the curtain hangs

Even though English often starts with the subject, Polish can put the location first:

• W nowym mieszkaniu stoi wysoki regał

But grammatically, wysoki regał is still the subject, so it remains nominative.

Polish word order is much more flexible than English word order.

English usually prefers:

• A tall bookcase stands in the new apartment

But Polish often puts the setting or location first, especially when introducing a scene:

• W nowym mieszkaniu stoi wysoki regał

This feels natural and descriptive, almost like In the new apartment, there is a tall bookcase.

So the Polish sentence is not strange or poetic. It is a very normal way to present what is in a place.

Because przy takes the locative case.

The base form is:

• okno = window

After przy, it becomes:

• przy oknie = by / near the window

So the noun changes to locative singular.

This is something you largely have to memorize with prepositions in Polish:

• w
  • locative for location
• przy
  • locative
• and so on

They are not the same.

• w oknie = in the window
• przy oknie = by / near the window

In this sentence, przy oknie wisi jasna firanka means the curtain is hanging by the window, which is the natural idea.

If you said w oknie wisi firanka, that could also be possible in some contexts, but it suggests the curtain is in the window space itself. Przy oknie is often the more natural phrasing for something located next to or at the window.

Because the nouns have different grammatical genders, and the adjectives must agree with them.

• regał is masculine
• firanka is feminine

So in nominative singular:

• masculine: wysoki regał
• feminine: jasna firanka

This is basic adjective agreement in Polish.

In this sentence, a links two parts of the description:

• W nowym mieszkaniu stoi wysoki regał, a przy oknie wisi jasna firanka.

Here a is often best understood as something like:

• and
• while
• and meanwhile
• whereas depending on context

It is very common in Polish when adding another element of a scene, especially with a slight contrast or shift in focus.

Using i would also mean and, but a often sounds more natural when moving from one part of the scene to another.

Polish has no articles like English a/an/the.

So:

• regał can mean a bookcase or the bookcase
• firanka can mean a curtain or the curtain

The exact meaning depends on context.

In this sentence, English would probably translate them as a tall bookcase and a light curtain, because the sentence is introducing them as part of the room.

Yes, Polish allows several word orders, but they do not all sound equally neutral.

The given version:

• W nowym mieszkaniu stoi wysoki regał...

is very natural because it introduces the location first and then presents what is there.

If you say:

• W nowym mieszkaniu wysoki regał stoi...

that puts extra emphasis on wysoki regał, almost as if contrasting it with something else.

So the original version is probably the most neutral and natural for a simple description.

Not exactly.

• firanka usually means a net curtain or sheer curtain
• zasłona usually means a heavier curtain or drape

So jasna firanka suggests a light, airy curtain, often white or pale, hanging at the window. This fits the verb wisi very naturally.