Gdy pada deszcz, wycieraczki pracują szybko, a szyba nadal nie jest czysta.

Yes. Gdy means when here. It introduces a time clause: Gdy pada deszcz = When it rains / When rain is falling.

A learner will also often see kiedy. In this sentence, gdy and kiedy are very close in meaning, and both would be natural. Gdy can sound a little more neutral or written, while kiedy is very common in everyday speech.

Polish commonly expresses this idea with pada deszcz, literally something like rain is falling. The verb is padać, which can mean to fall, and in weather expressions it is used for rain, snow, etc.

So:

• Pada deszcz = It is raining
• Pada śnieg = It is snowing

English uses the dummy subject it, but Polish does not need that here.

Pada is the 3rd person singular present tense form of padać.

It is singular because deszcz is singular. So grammatically, the sentence is built like rain falls rather than it rains.

Wycieraczki means wipers, and in this context it means windshield wipers.

The singular is wycieraczka. In other contexts, wycieraczka can also mean a doormat, so the exact meaning depends on context. Because the sentence mentions rain and a windshield/window, wycieraczki clearly means the car wipers here.

Because a car normally has two wipers, and Polish refers to them in the plural: wycieraczki.

So:

• wycieraczka = one wiper
• wycieraczki = wipers

The verb matches that plural subject, which is why we get pracują, not pracuje.

Yes. Pracować literally means to work, and it can be used not only for people but also for machines and devices.

So wycieraczki pracują szybko means the wipers are working quickly. This sounds natural in Polish. You could also hear other verbs in related contexts, but pracują is a very normal choice.

Pracują is the 3rd person plural present tense form of pracować.

It agrees with wycieraczki, which is plural:

• wycieraczka pracuje = the wiper works
• wycieraczki pracują = the wipers work

Here a means something like and, but with a slight contrast. In this sentence, it is close to and yet, while, or even but depending on how you translate it.

So:

• ..., a szyba nadal nie jest czysta suggests a contrast: the wipers are working fast, but the windshield still is not clean.

This is different from i, which is a more simple and without that contrasting feel.

Literally, szyba means a pane of glass or a window glass. In car-related context, it often refers to the windshield.

So in this sentence, szyba is best understood as the car window/windshield that the wipers are cleaning. Polish often uses the more general word, and the exact meaning comes from context.

Because szyba is the subject of the second clause: the windshield is still not clean.

In other words:

• szyba = nominative, because it is the thing being described
• szybę would be accusative, which you would expect if it were a direct object

Here we are not saying the wipers clean the windshield. We are saying the windshield is not clean, so szyba stays in the nominative.

Czysta is the feminine singular form of czysty = clean.

It has to agree with szyba, which is a feminine singular noun. That is why we get:

• czysty for masculine singular
• czysta for feminine singular
• czyste for neuter singular

Since szyba is feminine, the adjective must be czysta.

In standard Polish, you normally keep jest in sentences like this: szyba nie jest czysta = the windshield is not clean.

Polish does sometimes omit to be in certain styles or very compressed expressions, but in an ordinary sentence like this, jest is expected and natural.

Also note that nie is written separately from the verb:

• jest = is
• nie jest = is not

Nadal means still.

It shows that the situation continues despite what is happening before it. So the idea is: the wipers are working quickly, but the windshield still is not clean.

A similar word is wciąż, which also often means still. In many contexts, nadal and wciąż are very close.

Yes, Polish word order is more flexible than English word order, because endings carry a lot of grammatical information.

For example, this sentence could be rearranged in some ways for emphasis, such as putting nadal in a different place. But the version you have is very natural and neutral: Gdy pada deszcz, wycieraczki pracują szybko, a szyba nadal nie jest czysta.

So as a learner, this is a good basic model to copy.

There are commas for two reasons.

First, Gdy pada deszcz is a subordinate clause, and Polish normally separates such clauses with a comma.

Second, the sentence then joins two main ideas with a:

• wycieraczki pracują szybko
• szyba nadal nie jest czysta

So the commas help show the structure clearly:

1. time clause
2. first main clause
3. contrasting second main clause