Siostra stoi na drabinie i maluje sufit nową farbą.

Siostra is the subject of the sentence, so it appears in the nominative case.

Basic dictionary form:

• siostra = sister

In this sentence, siostra is the person doing the actions:

• stoi = is standing
• maluje = is painting

So Polish uses the nominative form siostra.

Polish often uses specific verbs for physical position instead of just to be.

• stać / stoi = to stand / is standing
• siedzieć / siedzi = to sit / is sitting
• leżeć / leży = to lie / is lying

So Siostra stoi na drabinie means The sister is standing on a ladder, not just The sister is on a ladder.

This is very natural in Polish.

After na meaning on, Polish can use different cases depending on whether there is:

• location: on something
• movement toward: onto something

Here the sister is already on the ladder, so this is location, and na takes the locative case.

• drabina = ladder
• na drabinie = on the ladder

Compare:

• stoi na drabinie = she is standing on the ladder
• wchodzi na drabinę = she is climbing onto the ladder

So:

• na + locative = location
• na + accusative = movement onto

Because na here requires the locative case, and drabina changes form in the locative.

• nominative: drabina
• locative: na drabinie

This is a normal noun ending pattern for many feminine nouns ending in -a.

Polish usually does not need subject pronouns if the verb already makes the subject clear.

• stoi = she/he/it stands
• maluje = she/he/it paints

Since the noun siostra is already there, adding ona would usually be unnecessary.

So Polish commonly says:

• Siostra stoi na drabinie i maluje sufit.

not:

• Siostra ona stoi...

Maluje is the 3rd person singular present tense of malować.

• malować = to paint
• maluje = he/she/it paints, is painting

Because the subject is siostra (one person, feminine), Polish uses the 3rd person singular form:

• siostra maluje = the sister paints / is painting

Also, Polish present tense often covers both:

• paints
• is painting

The exact English translation depends on context.

Malować is imperfective, which is the natural choice when describing an action in progress or a general activity.

Here the sentence describes what is happening:

• she is standing on a ladder
• she is painting the ceiling

So maluje fits well.

A perfective verb such as pomalować would focus more on completing the action:

• pomalować sufit = to paint the ceiling completely / to finish painting it

So:

• maluje sufit = she is painting the ceiling
• pomaluje sufit = she will paint / paint up the ceiling to completion

Sufit is the direct object of maluje, so it is in the accusative case.

However, for many masculine inanimate nouns, the accusative singular looks exactly like the nominative singular.

• nominative: sufit = ceiling
• accusative: sufit = ceiling

So even though it is the object, the form does not change.

That is why:

• maluje sufit = she is painting the ceiling

This phrase uses the instrumental case, because it expresses the material or means used to do something: with new paint.

• farba = paint
• instrumental singular: farbą

The adjective must agree with the noun:

• nowa farba = new paint
• nową farbą = with new paint

So:

• malować coś farbą = to paint something with paint

This is a very common Polish pattern.

Because adjectives must match the noun in:

• gender
• number
• case

Here the noun is:

• farba — feminine singular

And because the phrase is in the instrumental, the adjective must also be feminine singular instrumental:

• nominative: nowa farba
• instrumental: nową farbą

So both words change:

• nowa → nową
• farba → farbą

Yes. In this sentence, the most direct meaning is with new paint or using new paint.

Polish farba usually means:

• paint as a substance/material

So maluje sufit nową farbą most naturally means:

• she is painting the ceiling with new paint

If the context were different, English might sometimes phrase it as with a fresh coat of paint, but grammatically the Polish here is simply about the material used.

Yes, Polish word order is fairly flexible.

The neutral order here is:

• Siostra stoi na drabinie i maluje sufit nową farbą.

But other orders are possible, depending on emphasis:

• Siostra maluje sufit nową farbą, stojąc na drabinie.
• Na drabinie stoi siostra i maluje sufit nową farbą.
• Sufit siostra maluje nową farbą.

The original sentence sounds natural and straightforward. It presents:

1. who is involved
2. where she is
3. what she is doing

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

So:

• siostra can mean sister, a sister, or the sister
• drabina can mean a ladder or the ladder
• sufit can mean a ceiling or the ceiling

The exact meaning depends on context.

In this sentence, English would usually say:

• The sister is standing on a ladder and painting the ceiling with new paint or more naturally
• My/The sister is standing on a ladder and painting the ceiling with new paint

But Polish does not need separate article words.

The letter ą is a nasal vowel, but in real speech its pronunciation depends on what follows.

In farbą, the ą comes before the end of the word, and many speakers pronounce it approximately like:

• far-bom or far-bɔ̃ depending on accent and speaking style

For a learner, a practical approximation is:

• farbom

But it is still written farbą.

So:

• nową farbą is written with ą
• in actual speech, the nasal quality may sound slightly different from how you expect from spelling

Yes. Polish present tense often covers both meanings.

• maluje can mean paints
• maluje can also mean is painting

In this sentence, because it describes an ongoing scene, English usually prefers:

• is painting

So the most natural translation is:

• The sister is standing on a ladder and painting the ceiling with new paint.

But grammatically, the Polish present tense itself does not force a strict distinction between simple present and present continuous the way English often does.