Roślina doniczkowa więdnie.

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

• roślina = nominative singular
• roślinę = accusative singular

In Roślina doniczkowa więdnie, the plant is the thing performing the action/state of wilting, so nominative is required.

A very literal structure is:

• roślina = the plant
• więdnie = is wilting / wilts

So roślina is the correct form here.

Doniczkowa is an adjective describing roślina.

It agrees with roślina in:

• gender: feminine
• number: singular
• case: nominative

That is why you get:

• roślina — feminine singular nominative
• doniczkowa — feminine singular nominative adjective

This kind of agreement is a basic feature of Polish grammar: adjectives change their endings to match the nouns they describe.

In Polish, adjectives often come before the noun, but they can also come after it.

So both are possible:

• roślina doniczkowa
• doniczkowa roślina

However, roślina doniczkowa sounds very natural because it behaves almost like a fixed category name, similar to house plant / potted plant.

In general:

• adjective before noun often sounds more neutral or descriptive
• adjective after noun is also common, especially in set expressions, classifications, or more formal style

So this word order is normal and idiomatic.

Więdnie is the:

• 3rd person singular
• present tense
• form of the verb więdnąć (to wilt)

It is used with singular subjects such as:

• roślina więdnie = the plant is wilting
• kwiat więdnie = the flower is wilting

Some other present-tense forms are:

• ja więdnę = I am wilting
• ty więdniesz = you are wilting
• on/ona/ono więdnie = he/she/it is wilting
• my więdniemy = we are wilting
• wy więdniecie = you all are wilting
• oni/one więdną = they are wilting

It can mean either, depending on context.

Polish present tense often covers both:

• simple present: wilts
• present progressive: is wilting

So Roślina doniczkowa więdnie can be understood as:

• The houseplant is wilting or
• The houseplant wilts

In real usage, with this sentence, English usually prefers is wilting.

A rough English-friendly guide:

• Roślina ≈ rosh-LEE-na
• doniczkowa ≈ do-neech-KO-va
• więdnie ≈ VYEND-nye

A few important sounds:

• ś is a soft sh-like sound
• cz sounds like ch in chop
• w in Polish sounds like English v
• ie often sounds roughly like ye
• ń is a soft ny sound

A slightly more careful breakdown:

• Roślina: ro-śLI-na
• doniczkowa: do-nicz-KO-wa
• więdnie: WIĘD-nie

Stress in Polish usually falls on the second-to-last syllable:

• rośLIna
• doniczKOwa
• WIĘDnie

This is about aspect, which is very important in Polish verbs.

• więdnąć is imperfective: it describes an ongoing process
• zwiędnąć is perfective: it describes reaching the result, becoming wilted

So:

• Roślina więdnie = The plant is wilting.
  Focus: the process

• Roślina zwiędła = The plant has wilted / wilted.
  Focus: the completed result

This is a very common Polish distinction:

• imperfective = ongoing, repeated, or general
• perfective = completed event or result

Yes, you can.

• Roślina doniczkowa więdnie
• Doniczkowa roślina więdnie

Both are grammatically correct.

The difference is mostly about style, emphasis, and what sounds most natural in context.

• Roślina doniczkowa sounds like a category label: houseplant / potted plant
• Doniczkowa roślina feels a little more like ordinary adjective + noun description: a potted plant

In many situations, the original version sounds especially natural.

Yes:

• Roślina więdnie.

That simply means the plant is wilting.

Adding doniczkowa makes the noun phrase more specific:

• roślina = plant
• roślina doniczkowa = houseplant / potted plant

So doniczkowa is not grammatically necessary, but it adds information.

Because Polish usually does not use a separate word like English is in this type of present-tense sentence.

English:

• The houseplant is wilting

Polish:

• Roślina doniczkowa więdnie

The verb więdnie already contains the person and number information, so no extra present-tense to be is needed.

This is very normal in Polish:

• On pracuje. = He is working / He works
• Dziecko śpi. = The child is sleeping
• Roślina więdnie. = The plant is wilting

Yes, very much so. It is a common and natural phrase for a plant kept in a pot, especially a houseplant.

Learners should think of roślina doniczkowa as a useful vocabulary chunk, not just as two random words.

Other similar noun + adjective combinations in Polish also behave like set terms, for example:

• język polski = Polish language
• skrzynia biegów = gearbox
• szkoła podstawowa = primary school

So it is helpful to memorize roślina doniczkowa as a unit.

Both words change, because the adjective must agree with the noun.

Here are a few useful forms:

• Nominative: roślina doniczkowa
• Genitive: rośliny doniczkowej
• Dative: roślinie doniczkowej
• Accusative: roślinę doniczkową
• Instrumental: rośliną doniczkową
• Locative: roślinie doniczkowej

For example:

• Nie ma rośliny doniczkowej. = There is no houseplant.
• Widzę roślinę doniczkową. = I see a houseplant.
• Myślę o roślinie doniczkowej. = I am thinking about the houseplant.

This is a good example of how Polish noun and adjective endings work together.