Nagle usłyszałam domofon i pomyślałam, że to kurier.

Because the speaker is female and is talking about herself in the past tense.

In Polish past tense, the verb agrees with the speaker’s gender:

• usłyszałam = I heard / I caught the sound of (female speaker)
• pomyślałam = I thought (female speaker)

If the speaker were male, it would be:

• usłyszałem
• pomyślałem

So this sentence tells you that the speaker is a woman.

Because the sentence describes two completed events in the past:

1. Nagle usłyszałam domofon = suddenly I heard the intercom
2. i pomyślałam, że to kurier = and I thought that it was the courier

Polish past tense is often used exactly like English past tense here. The speaker is narrating what happened.

This is a very common question because Polish often distinguishes between an ongoing state and a completed event.

• słyszałam = I was hearing / I could hear
• usłyszałam = I heard, I caught the sound, I suddenly became aware of it

In this sentence, the idea is a single event: the speaker suddenly heard the intercom. So usłyszałam is the natural choice.

Compare:

• Słyszałam muzykę przez godzinę. = I could hear music for an hour.
• Nagle usłyszałam hałas. = Suddenly I heard a noise.

Again, this is about aspect.

• myślałam usually means I was thinking / I used to think
• pomyślałam means I thought in the sense of a single completed mental reaction

Here the speaker had one quick thought: that’s probably the courier. So pomyślałam fits better.

Compare:

• Myślałam o tym cały dzień. = I was thinking about it all day.
• Pomyślałam, że to on. = I thought it was him.

Nagle means suddenly.

It signals that something happened unexpectedly or abruptly. In this sentence, it sets the scene:

• Nagle usłyszałam domofon... = Suddenly, I heard the intercom...

It is very commonly placed near the start of the sentence, but Polish word order is flexible.

Domofon usually means an intercom system in a building, especially the kind used at the entrance to a block of flats or apartment building.

In this sentence, usłyszałam domofon does not mean that she literally heard the physical device itself. It means she heard the intercom buzz/ring.

So a natural English translation could be:

• I suddenly heard the intercom
• I suddenly heard the buzzer
• I suddenly heard the door intercom ring

Because domofon is the direct object of usłyszałam, and for an inanimate masculine noun, the accusative is the same as the nominative.

So:

• nominative: domofon
• accusative: domofon

That is why the form does not visibly change.

This is very common with masculine inanimate nouns in Polish.

Że means that and introduces a subordinate clause.

• pomyślałam, że... = I thought that...

So:

• pomyślałam, że to kurier = I thought that it was the courier

In English, that is often optional, but in Polish że is very normal and expected here.

In Polish, the verb to be (jest) is often omitted in the present tense, especially in simple identification statements with to.

So:

• To kurier. = It’s the courier.
• To mój brat. = This is my brother.

That means:

• pomyślałam, że to kurier literally looks like I thought that this/it courier, but naturally it means I thought it was the courier.

You could also say że to jest kurier, but it sounds a bit more explicit or emphatic. The shorter version is very natural.

After to, when identifying someone or saying what something is, Polish normally uses the nominative.

So:

• to kurier
• to lekarz
• to moja siostra

Even though English learners may expect another case, kurier here stays in the nominative because it is part of an identification structure: it’s the courier.

In everyday modern Polish, kurier most often means a courier/delivery person — someone delivering a parcel.

So in this sentence, the speaker likely heard the intercom and assumed a package delivery had arrived.

Depending on context, kurier can be translated as:

• courier
• delivery driver
• delivery person

Yes, but the verb forms must change.

A male speaker would say:

Nagle usłyszałem domofon i pomyślałem, że to kurier.

The only difference is:

• usłyszałam → usłyszałem
• pomyślałam → pomyślałem

Everything else stays the same.

No, Polish word order is relatively flexible, although some versions sound more natural than others.

The original sentence is very natural:

• Nagle usłyszałam domofon i pomyślałam, że to kurier.

You could also hear:

• Usłyszałam nagle domofon i pomyślałam, że to kurier.
• Pomyślałam, że to kurier, kiedy nagle usłyszałam domofon.

But the original order is good because it presents the events in a natural sequence:

1. suddenly hearing the intercom
2. then thinking it was the courier

Yes. I simply means and, but here it links two actions in sequence:

• I heard the intercom
• and I thought it was the courier

So it does not just connect two unrelated facts. It suggests that the second action followed naturally from the first.

In other words:

I heard the intercom, and then I thought it was the courier.

A rough pronunciation guide for an English speaker could be:

Nagle usłyszałam domofon i pomyślałam, że to kurier.
NAH-gleh oo-swy-SHAH-wam doh-MOH-fon ee poh-mysh-WAH-wam zheh toh KOO-ryer

A few useful points:

• ł sounds like English w
• sz sounds like sh
• ż in że sounds like the s in measure
• ie in kurier helps create roughly KOO-ryer

This is only approximate, but it helps with a first reading.