Wilgotność rośnie w miarę jak zraszam roślinę doniczkową.

Because wilgotność means humidity and it is the thing that is increasing.

In Polish, the subject is usually in the nominative case, and wilgotność is nominative singular. The verb rośnie agrees with it: both are 3rd person singular.

So structurally:

• Wilgotność = the subject
• rośnie = is rising / increases

Rośnie is the present-tense form of rosnąć, which basically means to grow or to increase.

In this sentence, it does not mean something is physically growing taller. It means a level is going up:

• Wilgotność rośnie = The humidity is increasing

This is very natural in Polish. Similar examples:

• Temperatura rośnie = The temperature is rising
• Ciśnienie rośnie = The pressure is increasing

W miarę jak is a conjunction meaning something like:

• as
• while
• in proportion as
• the more / as ... goes on

It introduces a clause showing that one thing changes gradually alongside another.

So:

• Wilgotność rośnie w miarę jak zraszam roślinę doniczkową.

means that the humidity goes up as the spraying/misting happens.

A very literal feel would be:

• Humidity rises in step with my misting the potted plant.

This is a fixed expression, so learners should treat w miarę jak as a whole.

Zraszam comes from zraszać, which means to sprinkle, to mist, or to spray lightly with water.

It is a good choice for plants, especially when you mean giving them a light spray rather than soaking them.

Possible related verbs:

• podlewać = to water (usually the soil/root area)
• spryskiwać = to spray
• zraszać = to mist / lightly spray with water

So zraszam roślinę doniczkową suggests I am misting the houseplant/potted plant.

Because the sentence describes an action happening at the same time as the humidity increases.

Zraszam is the 1st person singular present tense of zraszać:

• (ja) zraszam = I mist / I am misting

In Polish, the present tense often covers both:

• I mist
• I am misting

The exact English translation depends on context.

Here it feels very natural as an ongoing action:

• Humidity is increasing as I am misting the potted plant.

Because the sentence focuses on an ongoing process, not on a completed single action.

Zraszać is the imperfective verb. That makes sense here because:

• the misting is happening over time
• the humidity is increasing during that process
• the action is viewed from the inside, as it unfolds

If you used a perfective verb, it would usually suggest a completed act, which would not fit as well with the gradual sense of w miarę jak.

So imperfective is the natural choice.

Because roślinę doniczkową is in the accusative case, used for the direct object of zraszam.

You are misting what? → roślinę doniczkową

Base form (nominative):

• roślina doniczkowa = a potted plant

Accusative singular:

• roślinę doniczkową

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

For a feminine singular noun like roślina, the accusative often looks like this:

• -a → -ę
• adjective -a → -ą

So:

• roślina → roślinę
• doniczkowa → doniczkową

Roślina doniczkowa means potted plant or houseplant.

Breakdown:

• roślina = plant
• doniczkowa = pot-related / potted

The adjective doniczkowy / doniczkowa / doniczkowe comes from doniczka, meaning flowerpot / plant pot.

So a roślina doniczkowa is a plant kept in a pot, often indoors.

Because Polish has no articles.

English says:

• the humidity
• a potted plant
• the potted plant

Polish normally just says:

• wilgotność
• roślina doniczkowa
• roślinę doniczkową

Whether it means a or the depends on context.

So in this sentence, roślinę doniczkową could be understood as:

• a potted plant
• the potted plant

The surrounding context tells you which one is intended.

Yes. Polish word order is more flexible than English because case endings show grammatical relationships.

The neutral order here is:

• Wilgotność rośnie w miarę jak zraszam roślinę doniczkową.

But you could also say, for example:

• W miarę jak zraszam roślinę doniczkową, wilgotność rośnie.

This version puts more focus on the time/condition clause first.

You could also move things around for emphasis, but not every order sounds equally natural. The original sentence is smooth and standard.

No—not in this sentence.

Here w miarę jak works as a conjunction introducing a whole clause:

• w miarę jak zraszam roślinę doniczkową

So it is not directly assigning a case to a noun here.

That said, Polish also has w miarę in another pattern:

• w miarę możliwości = as far as possible
• w miarę potrzeb = as needed

In those expressions, w miarę is followed by a noun, often in the genitive. But that is a different structure from w miarę jak + clause.

Because the verb ending already tells you.

In Polish, subject pronouns are often omitted when they are clear from the verb form.

• zraszam = I mist / I am misting

The ending -am tells you it is 1st person singular, so ja is unnecessary.

You could say:

• Ja zraszam roślinę doniczkową

but that would usually add emphasis, like I’m the one misting the plant.

Without ja, the sentence sounds more neutral and natural.

A few parts may stand out to English speakers:

• wilgotność
  The ending -ść is a soft sh/ch-like cluster.
• rośnie
  ś is a soft sh sound; nie is roughly nye.
• zraszam
  The rz sounds like ż in modern Polish, similar to the s in measure.
• roślinę
  Final ę is a nasal vowel, though in normal speech it is often less strongly nasal than learners expect.
• doniczkową
  Final ą is also nasal.

A rough English-friendly approximation would be:

• veel-got-noshch rosh-nye v mya-rę yakh zra-sham rosh-lee-nę do-neech-ko-vą

That is only approximate, but it may help you notice the main sounds. The real Polish pronunciation is smoother and more connected than any English spelling can show.

It can be either, depending on context.

Polish present tense is often flexible enough to mean:

• a general tendency
• a habitual action
• something happening now

So this sentence could mean:

• Humidity rises as I mist the potted plant
  (general observation)

or

• Humidity is rising as I’m misting the potted plant
  (right now)

Both are possible. Context tells you which interpretation is intended.