Learn Hardcore Polish: Gdy rośnie czynsz albo cena gazu, musimy oszczędzać więcej pieniędzy. - When the rent or the price of gas rises, we have to save more money.

gdy – slightly more formal/literary; used mostly as a conjunction, not as a question word. Often feels like “whenever”.
kiedy – completely natural in speech, also used as the question word “when?”.

In everyday usage here, gdy and kiedy are interchangeable.

Why is it rośnie (singular) even though we have two things: czynsz albo cena gazu?

Because albo means “or”, and the phrase is understood as:

When either the rent or the price of gas goes up…

So at any given time, we’re talking about one of them. In Polish, with albo used in this “either A or B” sense, you normally keep the verb in the singular, matching one singular noun:

rośnie czynsz – the rent is going up
rośnie cena gazu – the price of gas is going up
rośnie czynsz albo cena gazu – the rent or the gas price is going up

If you wanted to say that both rise together, you’d use i (“and”) and a plural verb:

Gdy rosną czynsz i cena gazu, musimy oszczędzać więcej pieniędzy.
When the rent and the price of gas go up, we must save more money.

Here rosną is 3rd person plural.

Could the word order be Gdy czynsz albo cena gazu rośnie… instead?

Yes, that’s also correct:

Gdy rośnie czynsz albo cena gazu…
Gdy czynsz albo cena gazu rośnie…

Both are grammatical and natural.

Polish has relatively flexible word order. The differences are mainly about emphasis:

Gdy rośnie czynsz albo cena gazu… – the process of rising is slightly foregrounded.
Gdy czynsz albo cena gazu rośnie… – the rent or gas price is put a bit more in focus.

In normal conversation, both are fine and don’t sound strange.

Why is it cena gazu, not cena gaz?

Because cena (price) takes a genitive after it when you say “the price of X”.

cena czego? – price of what?
- cena gazu – price of gas
- cena chleba – price of bread
- cena biletu – price of the ticket

So:

gaz – nominative (dictionary form): “gas”
gazu – genitive: “of gas”

The pattern is cena + [genitive], just like “price of gas” in English.

What does musimy literally mean, and why is oszczędzać in the infinitive?

Musimy is 1st person plural present of musieć – “to have to / must”.

my musimy – we must / we have to

In Polish, modal verbs like musieć are followed by the infinitive form of the main verb, just like English “must save” (not must saves).

So:

musimy oszczędzać – we must save
- musimy – we must
- oszczędzać – to save (infinitive)

You cannot say:

✖ musimy oszczędzamy – incorrect

The correct pattern is always:

musimy + infinitive
- musimy pracować – we must work
- musimy zapłacić – we must pay
- musimy oszczędzać – we must save

What’s the difference between oszczędzać and zaoszczędzić here? Could I say musimy zaoszczędzić więcej pieniędzy?

Yes, you can say musimy zaoszczędzić więcej pieniędzy, but the meaning changes slightly because of aspect.

oszczędzać – imperfective, focuses on an ongoing / repeated process
- musimy oszczędzać więcej pieniędzy
  = We must save more money (in general, as a habit, over time).
zaoszczędzić – perfective, focuses on a single completed result
- musimy zaoszczędzić więcej pieniędzy
  = We must manage to save up more money (for some concrete goal or by a certain point).

In your original sentence, oszczędzać fits very well because rising rent/gas is usually a long‑term or recurring situation, and the saving is also ongoing.

Why is it więcej pieniędzy, not więcej pieniądze?

Because więcej (“more [of]”) requires the genitive case after it.

więcej czego? – more of what?
- więcej pieniędzy – more money
- więcej czasu – more time
- więcej pracy – more work

Pieniądze is the nominative plural (“money”), but after więcej we need the genitive plural: pieniędzy.

So:

pieniądze – nominative plural (dictionary form)
pieniędzy – genitive plural

That’s why:

✔ więcej pieniędzy – correct
✖ więcej pieniądze – incorrect (wrong case after więcej)

This is the same pattern you see with dużo, mało, trochę, mniej, więcej: they all take genitive.

What is the basic dictionary form of pieniędzy, and why is it so irregular?

The base form you’ll find in dictionaries is pieniądze.

pieniądze – nominative plural (“money”)
pieniędzy – genitive plural (“of money”)

Note two useful facts:

Pieniądze is grammatically plural‑only in everyday usage (you don’t normally say a singular like “a money”).
There is a singular noun pieniądz, but it means “a monetary unit / a coin” and is used more in economics or formal language, not in everyday “I don’t have money” type sentences.

The forms are a bit irregular because of historical sound changes. The main ones to learn are:

Nom./Acc. pl.: pieniądze
Gen. pl.: pieniędzy

If you remember that więcej needs genitive, it will help you recall więcej pieniędzy.

Is there any difference between albo and lub in this sentence?

Both albo and lub translate roughly as or, and in this sentence they’re practically interchangeable:

Gdy rośnie czynsz albo cena gazu…
Gdy rośnie czynsz lub cena gazu…

Subtle tendencies:

albo – a bit more colloquial, often felt as “either A or B” (more exclusive).
lub – slightly more formal / written, and often understood as inclusive “A or B or both”.

Here, because you only have one verb in the singular (rośnie), the idea is essentially “when either the rent or the price of gas goes up…”. Most speakers wouldn’t feel a strong difference between albo and lub in this specific sentence.

Could I use jeśli instead of gdy: Jeśli rośnie czynsz albo cena gazu…?

Yes, that’s also possible:

Jeśli rośnie czynsz albo cena gazu, musimy oszczędzać więcej pieniędzy.

Nuance:

gdy – mainly temporal: when / whenever (talks about the time something happens).
jeśli – conditional: if (focus on the condition/hypothesis).

So:

Gdy rośnie czynsz… – “When/whenever the rent goes up, we must save more money.” (a recurring, real‑world situation).
Jeśli rośnie czynsz… – “If the rent goes up, we must save more money.” (more like a condition that may or may not happen).

Both are grammatical; you choose based on whether you want to stress time (gdy) or condition (jeśli).

Could I say kiedy czynsz albo cena gazu wzrasta instead of rośnie? Is wzrastać better here?

You can say:

Kiedy czynsz albo cena gazu wzrasta, musimy oszczędzać więcej pieniędzy.

It’s perfectly correct. The nuance between rosnąć and wzrastać:

rosnąć – to grow, rise, increase (very common, neutral, used with prices, children, plants, numbers, etc.).
wzrastać – to increase, rise (often slightly more formal or bookish; common with numbers, indicators, statistics).

In everyday conversation about bills, rosnąć is probably the most natural:

rosną ceny – prices are rising
rośnie czynsz – the rent is going up

Wzrastać sounds fine but a bit more formal/economic‑style: useful in reports, news, etc. Grammatically, both take singular here (wzrasta, not wzrastają), for the same reason as with rośnie.

How do you pronounce czynsz, and what’s happening in a word like oszczędzać?

Czynsz

Syllables: 1 (it’s just one clump).

Approximate breakdown for an English speaker:

cz – like ch in chocolate, but a bit harder / more retroflex.
y – a vowel similar to the i in bit, but pronounced further back in the mouth.
n – normal n.
sz – like sh in ship.

So czynsz is roughly like: chynsh (one syllable).

oszczędzać

Syllables: o‑szczę‑dzać (stress on the second syllable: oszCZĘdzać).

Key clusters:

szcz – pronounced like a quick shch, as in fresh cheese said quickly.
ę before d – sounds like en (nasalized e): szczęd ≈ shchend.
dz before a – like dza in kids are.
Final ć – a soft “ch” sound, similar to ch in cheap, but with the tongue more towards the front of the palate.

Approximate English‑style rendering: osh-CHEN-dzach (with the main stress on CHEN).