Learn Hardcore Polish: Muszę sprawdzić adres na tej karcie. - I must check the address on this card.

All three are possible translations. Muszę most often feels like “I have to/I need to,” expressing strong necessity about the speaker. For a softer “should,” use powinienem/powinnam. For impersonal necessity, use trzeba: Trzeba sprawdzić adres = “It’s necessary to check the address.”

Why is the verb perfective (sprawdzić) and not imperfective (sprawdzać)?

Aspect choice shows what kind of “checking” you mean:

Muszę sprawdzić = I need to check it once and complete the task (single, complete action).
Muszę sprawdzać = I have to be checking it regularly/habitually (repeated process). Here a one-off check is intended, so perfective sprawdzić fits.

After muszę, should the next verb be an infinitive? Why not “muszę sprawdzam/sprawdzę”?

Yes: use muszę + infinitive. So: Muszę sprawdzić... Not muszę sprawdzam and not muszę sprawdzę. For future obligation, change the auxiliary: Będę musiał/musiała sprawdzić... (“I will have to check...”)

What case is adres, and why doesn’t it change?

It’s the direct object in the accusative. Inanimate masculine nouns like adres have the same form in nominative and accusative, so it remains adres.

Why is it “na tej karcie” and not “na ta karta”?

With a static location (“on” something), na takes the locative case. Feminine karta becomes karcie in the locative, and ta becomes tej. Hence: na tej karcie = “on this card.”

When would it be “na tę kartę” (or colloquial “na tą kartę”) instead?

Use accusative after na to express motion onto a surface:

Połóż to na tę kartę = Put it onto this card. Also, idiomatically with verbs of looking: Patrzę na tę kartę = I’m looking at this card. Note: standard feminine accusative is tę; many speakers say tą in everyday speech. Don’t confuse with instrumental tą kartą = “with this card.”

Can I change the word order?

Yes. All of these are grammatical, with different emphasis:

Neutral: Muszę sprawdzić adres na tej karcie.
Focus on location: Muszę sprawdzić na tej karcie adres.
Contrastive focus on the object: Adres muszę sprawdzić na tej karcie.

Do I need the pronoun “ja”?

No. The ending in Muszę already shows “I.” Ja muszę... adds emphasis or contrast (“I, specifically, have to...”)

How do I pronounce the tricky parts?

sz (muszę) = “sh,” retroflex.
ę (muszę) = nasal “e”; at word end it often sounds like a lightly nasalized “e.”
dzi (sprawdzić) = soft “dj” [dʑ].
ć (sprawdzić) = very soft “ch” [t͡ɕ].
j (tej) = “y” in “yes.”
cie (karcie) = “ch-yeh” [t͡ɕe].

Where is the stress?

Polish stress almost always falls on the second-to-last syllable of each word: mu‑SZĘ, spraw‑DZIĆ, A‑dres, TEJ, KAR‑cie.

How do I say “I will have to check the address on this card”?

Male speaker: Będę musiał sprawdzić adres na tej karcie.
Female speaker: Będę musiała sprawdzić adres na tej karcie.

How do I replace “on this card” with a pronoun?

Since karta is feminine, use feminine locative: na niej. Example: Muszę sprawdzić adres na niej. With masculine/neuter referents, use na nim.

Is karta always the right word for “card”?

Often yes (e.g., karta SIM, karta kredytowa). But:

A small sheet of paper is kartka.
A business card is wizytówka.
A restaurant menu is karta dań (“menu”). Context determines the best noun.