Learn Hardcore Polish: Kiedy pada deszcz, najgorszy dzień staje się lepszy z gorącą czekoladą. - When it rains, the worst day becomes better with hot chocolate.

kiedy is a subordinating conjunction meaning when. It introduces the temporal clause at the beginning of the sentence, indicating the time frame for the action in the main clause.

Can kiedy be replaced with gdy here, and are there any differences?

Yes. gdy is a near-synonym of kiedy and also means when. In most contexts they are interchangeable. kiedy is slightly more neutral, while gdy can sound a bit more formal or literary. Avoid using jak, which means how rather than when.

Why is there a comma after Kiedy pada deszcz?

In Polish, a subordinate clause is separated by a comma when it appears at the start (or end) of a sentence. The comma marks the boundary between the introductory time clause and the main clause.

Why is deszcz in the nominative case in pada deszcz?

The verb pada (“it falls”) here is intransitive, so deszcz functions as the subject and takes the nominative case. There is no direct object in this construction.

What does staje się mean, and what is the role of się?

staje się means becomes. The particle się makes the verb reflexive, forming stawać się (“to become”), which describes a change of state.

How is najgorszy formed, and why is it used here?

najgorszy is the superlative of zły (bad). You form it by adding the prefix naj- to the comparative gorszy, yielding najgorszy (the worst). It emphasizes that the day is as bad as it can be.

Why is lepszy used in staje się lepszy, and how does it relate to dobry?

lepszy is the comparative form of dobry (good). It means better. Since the sentence describes the worst day improving, the comparative is the correct choice to show that it becomes better than it was.

Why does the sentence use z plus the instrumental gorącą czekoladą, and how do you form that case?

After the preposition z meaning with (in the sense of accompaniment), Polish requires the instrumental case. gorąca czekolada (feminine noun) changes -a to -ą to become gorącą czekoladą in the singular instrumental.

Is the word order flexible? Could you say Najgorszy dzień z gorącą czekoladą staje się lepszy, kiedy pada deszcz?

Yes. Polish has relatively free word order. You can move phrases around for emphasis or style, and the overall meaning remains the same. The original order is simply the most neutral and common.