Learn Hardcore Polish: Kiedy jest zimno, wolę zostać w domu. - When it is cold, I prefer to stay at home.

You can sometimes drop jest in very informal or poetic language (e.g. kiedy zimno, kiedy ciemno…), but that’s not the default and it sounds stylistic. For a learner, it’s safest to keep jest here.

What’s the difference between kiedy and gdy? Could I say Gdy jest zimno, wolę zostać w domu?

Yes, you can; the sentence is still correct: Gdy jest zimno, wolę zostać w domu.

kiedy – very common in everyday speech; neutral.
gdy – a bit more formal or literary, but still normal in spoken language.

In this sentence they mean the same: when it’s cold. For daily conversation, kiedy is slightly more typical.

Why is there a comma in Kiedy jest zimno, wolę zostać w domu?

Polish almost always puts a comma between a dependent clause and the main clause.

Here, kiedy jest zimno is the dependent clause, and wolę zostać w domu is the main clause.

So the pattern is:

[Kiedy…] , [wolę…]

Even if English might skip the comma (When it’s cold I prefer…), Polish keeps it: Kiedy jest zimno, wolę…

What does wolę mean exactly, and what verb does it come from?

Wolę means I prefer. It’s the 1st person singular (ja) form of the verb woleć (to prefer).

Present tense of woleć:

(ja) wolę – I prefer
(ty) wolisz – you prefer (singular)
(on/ona/ono) woli – he/she/it prefers
(my) wolimy – we prefer
(wy) wolicie – you prefer (plural)
(oni/one) wolą – they prefer

In Polish you usually don’t need ja, so ja wolę is normally just wolę, unless you want to stress I in contrast to someone else.

Why is it wolę zostać and not wolę zostaję?

After wolę (I prefer), you use an infinitive: wolę + [infinitive].

zostać is the infinitive (to stay, to remain).
zostaję is the 1st person singular present (I am staying).

So the structure is like English I prefer to stay, not I prefer I stay.

Correct:

Wolę zostać w domu. – I prefer to stay at home.

Incorrect:

*Wolę zostaję w domu. (mix of “I prefer” + “I stay”)

Why is the verb zostać (perfective) used here and not zostawać (imperfective)?

Both are possible, but they sound a bit different:

wolę zostać w domu – very natural here; it sounds like a general choice in a specific situation: When it’s cold, my choice is to (stay / remain) at home (rather than go out).
wolę zostawać w domu – sounds more like a repeated, habitual action: I prefer staying at home (as a regular habit). It can work, but it’s less typical in this exact sentence.

In practice, with verbs of choosing/preferences (like wolę) and a specific situation (kiedy jest zimno), Polish very often uses the perfective infinitive: wolę zostać.

Why is it zostać w domu and not być w domu?

zostać w domu – stay / remain at home, usually implying you don’t go somewhere else. It focuses on the decision not to leave.
być w domu – be at home, just describes location, without the idea of choosing not to go out.

Here, you’re talking about what you prefer to do (not go out when it’s cold), so zostać w domu is more natural than być w domu.

Why is it w domu and not w dom?

Because of case. The preposition w (in) normally takes:

locative when you talk about location (where?): w domu – in/at home
accusative when you talk about movement into something (where to?): w dom is very rare and old-fashioned; in modern Polish you’d say do domu (to home).

Dom declines like this (singular):

nominative: dom – a house, home
locative: w domu – in the house / at home
genitive: do domu – to the house / to home

So w domu is the standard way to say at home.

Why don’t we say Ja wolę zostać w domu? Where is the “I”?

The “I” is contained in the verb ending -ę in wolę.

Polish verbs mark the person, so the subject pronoun (ja, ty, on…) is usually omitted when it’s clear from context.

Ja wolę zostać w domu. – grammatically correct, but you normally only use ja for emphasis or contrast:
- Ja wolę zostać w domu, a ty? – I prefer to stay at home, and you?

Can I change the word order and say Wolę zostać w domu, kiedy jest zimno?

Yes, that’s completely correct: Wolę zostać w domu, kiedy jest zimno.

Both orders are fine:

Kiedy jest zimno, wolę zostać w domu.
Wolę zostać w domu, kiedy jest zimno.

The meaning is the same. Starting with kiedy jest zimno slightly emphasizes the condition; starting with wolę slightly emphasizes your preference, but the difference is minimal.

Does kiedy here mean “when” or more like “whenever / if”?

It can cover all of these English nuances:

When it’s cold, I prefer to stay at home.
Whenever it’s cold, I prefer to stay at home.
Even close to: If it’s cold, I prefer to stay at home.

Polish kiedy in general statements like this is flexible and doesn’t force a strict distinction between when and whenever the way English sometimes does. The context (a general habit) makes it feel like whenever/when rather than a single specific time.