To był zwykły dzień w pracy, ale potem zadzwonił telefon.

Here to works like it/that/this in a general identifying sentence.

So To był zwykły dzień literally looks like That/it was an ordinary day.

In Polish, to is very common in sentences that identify or describe something:

• To jest dom. — This is a house.
• To był dobry dzień. — It was a good day.

It does not have to refer to a specific grammatical subject the way English it often does. It is a very natural Polish sentence opener.

Był is the past tense of być (to be).

The sentence is in the past, so Polish uses był:

• jest — is
• był — was

Because dzień is a masculine noun, the past form is masculine singular:

• był — masculine
• była — feminine
• było — neuter

So:

• To był dzień. — It was a day.
• To była noc. — It was a night.
• To było wydarzenie. — It was an event.

Because adjectives in Polish agree with the noun they describe.

The noun here is dzień (day), which is:

• singular
• masculine

So the adjective must also be masculine singular:

• zwykły dzień — an ordinary day

Compare:

• zwykła noc — an ordinary night
• zwykłe wydarzenie — an ordinary event

This is basic adjective-noun agreement.

Dzień is masculine.

In this sentence, you can tell from the agreement:

• był is masculine
• zwykły is masculine

So even if you did not know the gender of dzień, the surrounding words show it.

Many Polish nouns ending in a consonant are masculine, and dzień follows that pattern.

Because the preposition w usually requires the locative case when it means in or at a place.

The dictionary form is:

• praca — work

But after w, it changes to the locative:

• w pracy — at work / in work

So:

• praca — nominative
• w pracy — locative

This kind of case change is very common in Polish after prepositions.

In this sentence, the best English translation is at work.

Polish w pracy can often be translated as:

• at work
• sometimes in work depending on context, but much less often

Here zwykły dzień w pracy means an ordinary day at work.

It describes the setting, not the idea of employment in general.

Because Polish has no articles like a/an/the.

So zwykły dzień can mean:

• an ordinary day
• the ordinary day

The exact meaning depends on context.

In this sentence, English naturally uses an ordinary day, but Polish does not need any separate word for that.

Potem means then / afterward / later.

In this sentence:

• ale potem — but then / but afterward

It marks what happened next.

Potem and później are often similar, and in many contexts both can mean later.
But potem often feels especially natural in storytelling when one event follows another:

• Najpierw pracowałem, potem poszedłem do domu. — First I worked, then I went home.

So ale potem zadzwonił telefon sounds like a narrative progression: but then the phone rang.

This is a question of aspect, which is very important in Polish verbs.

• dzwonić — imperfective
• zadzwonić — perfective

In the past tense:

• dzwonił suggests ongoing/repeated ringing, or focuses on the process
• zadzwonił means the ringing happened as a complete event: rang / started ringing

In this sentence, the phone ringing is a single event that interrupts the ordinary day, so zadzwonił is the natural choice.

Compare:

• Telefon dzwonił przez pięć minut. — The phone was ringing for five minutes.
• Telefon zadzwonił. — The phone rang.

Both are possible.

Polish word order is more flexible than English, because case endings and verb forms carry a lot of grammatical information.

• Telefon zadzwonił is neutral and straightforward: The phone rang.
• Zadzwonił telefon is also natural, and it can sound a bit more narrative or event-focused, almost like then the phone rang.

So in this sentence, placing the verb first helps highlight the sudden event.

English usually keeps a fixed subject-verb order, but Polish can move things around for emphasis and style.

Yes. Telefon is the subject of zadzwonił.

Even though it comes after the verb, it is still the thing that performed the action in the sentence:

• zadzwonił telefon — the phone rang

Because telefon is masculine singular, the verb is also masculine singular:

• zadzwonił

So the agreement helps confirm that telefon is the subject.

Because ale means but, and in Polish it normally introduces a new clause, so it is preceded by a comma.

Here we have two parts:

• To był zwykły dzień w pracy
• ale potem zadzwonił telefon

The comma separates them, just as in English:

• It was an ordinary day at work, but then the phone rang.

Yes, you could, but it is not exactly the same in tone.

• zwykły = ordinary / usual
• normalny = normal

In many contexts they overlap, but zwykły dzień is the more natural choice for an ordinary day.

Normalny dzień is possible, but it may sound more like a normal day, emphasizing that nothing seemed unusual.

So:

• zwykły dzień — more idiomatic here
• normalny dzień — understandable, but slightly different in feel

A rough guide is: za-dzvo-neew

A few important points:

• dz is pronounced together as one sound
• w in Polish sounds like English v
• ł sounds like English w
• the stress is normally on the second-to-last syllable: za-dzwo-NIŁ

So zadzwonił sounds roughly like za-dzvo-NEEW.

As always, the rough English spelling is only an approximation, but it can help at first.