Rano prowadzę syna do przedszkola, a córkę odbiera później moja siostra.

Because they are in the accusative case, not the dictionary form.

In this sentence, syna and córkę are the direct objects of the verbs:

• prowadzę syna = I take/escort my son
• odbiera córkę = my sister picks up my daughter

Their base forms are:

• syn → syna in the accusative singular
• córka → córkę in the accusative singular

This is very common in Polish: the form of a noun changes depending on its role in the sentence.

Because the preposition do requires the genitive case.

So:

• przedszkole = preschool/kindergarten (dictionary form, nominative)
• do przedszkola = to the preschool (genitive after do)

Polish prepositions often determine the case of the noun that follows them. Here, do expresses movement toward a place, so do przedszkola means to preschool or to the kindergarten.

Here, a means something like and, but with a slight sense of contrast, switch of topic, or meanwhile/as for.

So:

• Rano prowadzę syna do przedszkola, a córkę odbiera później moja siostra.

has the feeling of:

• In the morning I take my son to preschool, and my daughter is picked up later by my sister.

Why a works well here:

• the first clause is about what I do for my son
• the second clause shifts to what happens with my daughter
• there is also a contrast in who does it

If you used i, it would sound more like simple addition. A is more natural in this kind of sentence.

Polish word order is much more flexible than English word order. The order here is used for focus and information flow.

The sentence first mentions:

• syna in the first clause

Then it contrasts that with:

• córkę at the start of the second clause

So putting córkę first helps create a neat parallel:

• syna ...
• a córkę ...

Then moja siostra comes later because it gives the important new information: who picks her up.

A more neutral order is also possible, for example:

• a moja siostra odbiera córkę później

But the original version sounds very natural and stylistically good.

By itself, rano means in the morning or morning-time.

In this sentence, it most naturally means:

• In the morning, I take my son to preschool...

It does not mean tomorrow morning unless the context makes that clear.

Compare:

• rano = in the morning
• jutro rano = tomorrow morning

Most likely, it describes a routine or a habitual action.

Polish present tense can be used both for:

• what is happening now
• what someone usually does

In this sentence, because of the context and wording, it sounds like a routine:

• Rano prowadzę syna do przedszkola...
• In the mornings / In the morning, I take my son to preschool...

So a natural English interpretation is often something like:

• In the morning I take my son to preschool, and my sister picks up my daughter later.

Because Polish usually does not need subject pronouns when the verb ending already shows the subject.

• prowadzę = I take / I lead
• the ending -ę already tells you the subject is I

So ja is unnecessary unless you want extra emphasis, for example:

• Ja prowadzę syna do przedszkola... = I’m the one who takes my son to preschool...

In the second clause, moja siostra is stated explicitly because the speaker needs to say who picks up the daughter.

The basic verb prowadzić can mean several things, including:

• to lead
• to conduct
• to drive
• to take/escort

In this sentence, prowadzę syna do przedszkola means something like:

• I take my son to preschool
• I walk/escort my son to preschool

It does not necessarily mean driving in a car. It often suggests accompanying someone, especially a child, to a place.

Here, odbiera means picks up.

So:

• córkę odbiera później moja siostra = my sister picks up my daughter later

The verb odbierać has several meanings in Polish depending on context, such as:

• to receive
• to collect
• to pick up
• to answer (for example, a phone)

In the context of children and school/preschool, odbierać very often means to pick someone up from there.

Później means later.

In this sentence, it most naturally means:

• later in the day
• later than the morning drop-off

So the timeline is:

• rano → I take the son to preschool
• później → my sister picks up the daughter later

The exact time is not specified. It is simply relative: not then, but later.

In some contexts, Polish can omit things that are understood, but here córkę is very useful and natural because it creates a clear contrast with syna.

Compare the structure:

• prowadzę syna
• a córkę odbiera...

This gives a strong, elegant pair:

• the son / the daughter
• I take / my sister picks up

So keeping córkę makes the sentence clearer and better balanced.

Because the end of a Polish clause often carries the newest or most important information.

Here, after hearing:

• a córkę odbiera później...

the listener naturally wonders:

• who picks her up later?

Then the sentence answers that at the end:

• moja siostra

So this word order helps highlight my sister as the important final piece of information. This is one reason the sentence sounds natural and well-structured in Polish.