Rano robię jajecznicę z pomidorem, a moja siostra woli naleśniki z dżemem.

Rano means in the morning.

In Polish, rano can be used by itself as an adverb, so you do not need a preposition like in. English says in the morning, but Polish often simply says rano.

So:

• Rano robię jajecznicę = In the morning, I make scrambled eggs

You could also see longer expressions like:

• o poranku = at dawn / in the early morning
• rano = the most common everyday choice for in the morning

Robię is the 1st person singular present form of robić, which usually means to do or to make.

Here it means I make:

• robię jajecznicę = I make scrambled eggs

This is very natural Polish. In English, we might say I make scrambled eggs or I cook scrambled eggs, but in Polish robić is common for preparing food.

Form:

• robić = infinitive
• robię = I do / I make

Because jajecznica is the direct object of the verb robię, it must be in the accusative case.

• nominative: jajecznica = scrambled eggs
• accusative: jajecznicę

So:

• Jajecznica jest smaczna. = Scrambled eggs are tasty.
  Here it is the subject, so nominative.
• Robię jajecznicę. = I’m making scrambled eggs.
  Here it is the object, so accusative.

This is very common with feminine nouns ending in -a:

• nominative -a
• accusative -ę

Because the preposition z meaning with requires the instrumental case.

• basic form: pomidor = tomato
• instrumental: pomidorem

So:

• z pomidorem = with tomato

This is a standard grammar rule:

• z + instrumental when it means with

Other examples:

• z serem = with cheese
• z mlekiem = with milk
• z siostrą = with (my) sister

Polish often uses the singular when talking about an ingredient or accompaniment in a general way.

So jajecznica z pomidorem is a perfectly natural phrase meaning scrambled eggs served or made with tomato.

However, z pomidorami is also possible and would mean more specifically with tomatoes.

The difference is often small and depends on how the speaker imagines the dish:

• z pomidorem = with tomato, tomato as an ingredient/addition
• z pomidorami = with tomatoes, possibly emphasizing several pieces or tomatoes in general

In everyday speech, both can make sense depending on context.

No, a and i are not exactly the same.

In this sentence, a introduces a contrast:

• Rano robię jajecznicę z pomidorem, a moja siostra woli naleśniki z dżemem.

This means something like:

• In the morning I make scrambled eggs with tomato, and/while my sister prefers pancakes with jam.

Here a is often best understood as:

• and
• while
• whereas
• sometimes almost but

It connects two ideas and highlights a difference between them.

By contrast, i is a more neutral and:

• Lubię kawę i herbatę. = I like coffee and tea.

So in your sentence, a is better because the two people prefer different foods.

Because moja siostra is the subject of the second clause, so it stays in the nominative case.

• nominative: moja siostra = my sister
• accusative: moją siostrę

Compare:

• Moja siostra woli naleśniki. = My sister prefers pancakes.
  (moja siostra = subject)
• Widzę moją siostrę. = I see my sister.
  (moją siostrę = object)

So the form in the sentence is correct because your sister is the one doing the preferring.

Woli means prefers.

It comes from the infinitive woleć = to prefer.

Forms:

• wolę = I prefer
• wolisz = you prefer
• woli = he/she/it prefers
• wolimy = we prefer
• wolicie = you all prefer
• wolą = they prefer

So:

• moja siostra woli naleśniki = my sister prefers pancakes

Naleśniki is the plural form of naleśnik (pancake / crêpe), and in this sentence it is the direct object of woli.

For many masculine inanimate plural nouns, the accusative plural looks the same as the nominative plural.

So:

• nominative plural: naleśniki
• accusative plural: naleśniki

That is why the form does not change here.

Compare:

• Naleśniki są smaczne. = Pancakes are tasty.
• Lubię naleśniki. = I like pancakes.

Same form, different function.

Naleśniki are thin pancakes, more like crêpes than thick American pancakes.

They can be sweet or savory. In this sentence:

• naleśniki z dżemem = pancakes/crêpes with jam

So if an English speaker imagines fluffy breakfast pancakes, that is not quite the same thing. Polish naleśniki are usually thin and folded or rolled.

For the same reason as z pomidorem: the preposition z meaning with takes the instrumental case.

• basic form: dżem = jam
• instrumental: dżemem

So:

• z dżemem = with jam

This pattern is very important in Polish:

• z cukrem = with sugar
• z masłem = with butter
• z dżemem = with jam

Yes. Polish word order is more flexible than English word order because the case endings show the grammatical roles.

The original sentence is very natural:

• Rano robię jajecznicę z pomidorem, a moja siostra woli naleśniki z dżemem.

But you could move parts around for emphasis, for example:

• Jajecznicę z pomidorem robię rano, a moja siostra woli naleśniki z dżemem.
  This emphasizes scrambled eggs with tomato.
• Moja siostra woli naleśniki z dżemem, a ja rano robię jajecznicę z pomidorem.
  This starts with my sister and her preference.

Even though different orders are possible, the original version sounds neutral and natural.

By default, it sounds like a habit or a usual preference:

• In the morning I make scrambled eggs with tomato, and my sister prefers pancakes with jam.

The present tense in Polish often works like the English simple present for routines and general truths.

Without extra context, it does not strongly suggest right now at this moment. If you wanted to make the ongoing meaning clearer, context would usually do that.

A rough English-friendly guide:

• rano ≈ RAH-no
• robię ≈ RO-byeh
  The final ę is nasal, but in normal speech it is often close to -e before a pause.
• jajecznicę ≈ ya-yech-NYEE-tseh
• pomidorem ≈ po-mee-DO-rem
• siostra ≈ SHOS-tra
• woleć / woli ≈ VO-lech / VO-lee
• naleśniki ≈ na-lesh-NEE-kee
• dżemem ≈ JHE-mehm

A few useful sound notes:

• j in Polish sounds like English y
• cz sounds like ch in chop, but harder
• ś sounds like a soft sh
• dż sounds like j in jam

Not with exactly the same meaning.

• lubić = to like
• woleć = to prefer

So:

• Moja siostra lubi naleśniki z dżemem. = My sister likes pancakes with jam.
• Moja siostra woli naleśniki z dżemem. = My sister prefers pancakes with jam.

Woli implies a comparison or choice: she likes them better than some alternative. In this sentence, that fits well because there is a contrast between what I make and what my sister prefers.