Musimy ograniczyć wydatki.

Because Polish usually does not need subject pronouns when the verb already shows who is doing the action.

In musimy, the ending -my tells you the subject is we. So:

• musimy = we must / we have to

You can add my (we) for emphasis:

• My musimy ograniczyć wydatki.

But in a neutral sentence, that usually sounds unnecessary.

Musimy is the 1st person plural form of the verb musieć (to have to / must).

Present-tense forms of musieć are:

• muszę – I must
• musisz – you must
• musi – he/she/it must
• musimy – we must
• musicie – you (plural) must
• muszą – they must

So in this sentence, musimy means we must or we have to.

Because after musieć, Polish normally uses an infinitive.

So the pattern is:

• musieć + infinitive

Examples:

• Muszę pracować. – I have to work.
• Musimy wyjść. – We have to leave.
• Musimy ograniczyć wydatki. – We must reduce expenses.

This works a lot like English must + base verb.

This is a very common question, because it involves aspect, which is very important in Polish verbs.

• ograniczyć = perfective
• ograniczać = imperfective

In simple terms:

• ograniczyć focuses on achieving the result: reducing, cutting down, bringing something under control
• ograniczać focuses on the process / repeated action / general activity of reducing

So:

• Musimy ograniczyć wydatki.
  = We need to reduce expenses, with focus on the result.

Compare:

• Musimy ograniczać wydatki.
  = We need to be reducing / keep reducing expenses, with more focus on the ongoing process.

In many practical situations, the perfective ograniczyć is the more natural choice when someone means we need to cut expenses.

Here wydatki is in the accusative plural, because it is the direct object of the verb ograniczyć.

We are reducing what?
→ wydatki

The dictionary form is:

• wydatek – an expense

Plural:

• wydatki – expenses

For many masculine inanimate nouns, the accusative plural looks the same as the nominative plural, and that is what happens here:

• nominative plural: wydatki
• accusative plural: wydatki

So even though the form looks unchanged, its function in the sentence is accusative.

The singular is wydatek.

• wydatek – an expense / an expenditure
• wydatki – expenses / expenditures / spending items

In everyday Polish, wydatki is very common when talking about money, budgets, household costs, government spending, and so on.

It often refers to expenses as a group, not just one individual purchase.

Yes, Polish word order is more flexible than English, but the original order is the most neutral and natural.

Neutral order:

• Musimy ograniczyć wydatki.

You might also hear:

• Wydatki musimy ograniczyć. – emphasizes expenses
• Ograniczyć wydatki musimy. – emphasizes the need to reduce

These alternatives are possible, but they sound more marked or emphatic. If you are learning, the safest default is the original version.

A rough pronunciation guide is:

• Musimy ≈ moo-SHEE-mih
• ograniczyć ≈ oh-grah-NEE-chitch
• wydatki ≈ vih-DAHT-kee

A few useful sound notes:

• si in musimy sounds like a soft sh-like sound: ś
• cz in ograniczyć sounds like English ch
• final ć is a softer sound, a bit like a very soft ch
• wy is not like English why; it is more like vih or vɨ

The stress is usually on the second-to-last syllable:

• mu-SI-my
• o-gra-NI-czyć
• wy-DAT-ki

Yes, and it is a useful comparison.

• Musimy ograniczyć wydatki. = We must reduce expenses.
• Trzeba ograniczyć wydatki. = It is necessary to reduce expenses / One has to reduce expenses.

The difference is that musimy clearly says we are the ones responsible, while trzeba sounds more impersonal and general.

So if you want a direct statement about our obligation, musimy is better.

Very often, yes. That is the normal pattern when musieć means must / have to.

Examples:

• Muszę iść. – I have to go.
• Musisz czekać. – You have to wait.
• Musimy ograniczyć wydatki. – We have to reduce expenses.

So in beginner and intermediate Polish, it is very useful to remember:

• musieć + infinitive

Yes. In many contexts, Polish musimy can correspond to both English we must and we have to.

Which English translation sounds best depends on tone:

• we must can sound a bit stronger or more formal
• we have to can sound more everyday

But the Polish sentence itself works naturally for both.

Yes: it is a classic perfective / imperfective pair, and this matters a lot in Polish.

A good shortcut is:

• ograniczać = to be reducing / to reduce in general / repeatedly
• ograniczyć = to reduce successfully / to cut down

Examples:

• Chcemy ograniczać koszty.
  We want to keep reducing costs / work on reducing costs.
• Chcemy ograniczyć koszty.
  We want to reduce costs (achieve that reduction).

In your sentence, the speaker is presenting reduction as a goal that needs to be accomplished, so ograniczyć fits very well.