Roślina doniczkowa potrzebuje więcej wody w miarę jak nasłonecznienie rośnie.

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

• roślina = a plant
• doniczkowa = potted / houseplant-related

Both words are feminine singular nominative, and the adjective doniczkowa agrees with roślina in gender, number, and case.

It comes from doniczka, which means flowerpot or plant pot.

So roślina doniczkowa literally means something like pot plant or potted plant. In natural English, it often corresponds to houseplant or potted plant.

It is an adjective formed from the noun doniczka, and its ending changes to match roślina.

Potrzebuje is the 3rd person singular present tense form of potrzebować = to need.

It matches the subject roślina doniczkowa, which is singular:

• ja potrzebuję = I need
• ty potrzebujesz = you need
• on/ona/ono potrzebuje = he/she/it needs

So here, roślina doniczkowa potrzebuje means the potted plant needs.

Because więcej is used for greater quantity, while bardziej is used for greater degree.

Here we are talking about more water, which is a quantity, so Polish uses więcej wody.

Compare:

• więcej wody = more water
• bardziej zielona = greener / more green
• bardziej ostrożnie = more carefully

So bardziej wody would be wrong.

Because wody is the genitive singular form of woda.

There are two reasons this makes sense here:

1. potrzebować normally takes the genitive:

   • potrzebować wody
   • potrzebować pomocy
   • potrzebować czasu

2. więcej also commonly requires a following noun in the genitive:

   • więcej wody
   • więcej czasu
   • więcej pieniędzy

So więcej wody is exactly the expected form.

W miarę jak is a fixed expression meaning as, as/while, or more precisely in proportion as.

It is used when one thing changes gradually while another thing also changes.

In this sentence, it means that the plant needs more water as the sunlight increases.

This is different from w miarę by itself, which can also mean things like moderately or as needed in other contexts. Here, the full conjunction is w miarę jak.

Usually not in this structure.

Here w miarę jak works as a full conjunction introducing the clause nasłonecznienie rośnie. If you remove jak, the sentence stops sounding natural in this meaning.

A different structure is possible, for example:

• w miarę wzrostu nasłonecznienia = with the increase in sunlight

But that is a different grammatical construction.

Nasłonecznienie is a neuter noun meaning sun exposure, amount of sunlight, or insolation.

It is a somewhat more formal or technical word than just słońce. It focuses on the degree of exposure to sunlight, not simply the sun as an object.

So this sentence sounds a bit more precise than something like:

• im więcej słońca, tym...

Both are understandable, but nasłonecznienie sounds more exact.

Because the subject of that clause is nasłonecznienie, which is singular.

• nasłonecznienie rośnie = the sun exposure increases
• warunki rosną would be plural, so then you would use rosną

The verb rośnie is the 3rd person singular present form of rosnąć = to grow / increase.

No, Polish word order is fairly flexible.

This sentence could also be written as:

• W miarę jak nasłonecznienie rośnie, roślina doniczkowa potrzebuje więcej wody.

That version is very natural too. The meaning stays the same.

The original sentence starts with roślina doniczkowa, which puts the plant in focus first. The alternative starts with the changing condition, w miarę jak nasłonecznienie rośnie.

Yes, absolutely. That is a very common alternative.

For example:

• Im większe nasłonecznienie, tym więcej wody potrzebuje roślina doniczkowa.

This means essentially the same thing: the greater the sun exposure, the more water the plant needs.

A learner should recognize both patterns:

• w miarę jak...
• im..., tym...

They are both natural, but the second one often sounds a bit more compact and explicitly comparative.

Yes, but the nuance is slightly different.

• roślina doniczkowa = a potted plant / houseplant as a type
• roślina w doniczce = a plant in a pot

The first is a more standard label for this kind of plant. The second is more literal and descriptive.

So in this sentence, roślina doniczkowa sounds very natural.

Because Polish does not have articles like English a and the.

So roślina doniczkowa can mean:

• a potted plant
• the potted plant

Which one is meant depends on context. That is normal in Polish.