Pielęgniarka mówi, że lekarstwo pomoże na gorączkę.

Pielęgniarka is nominative singular feminine. It is the subject of the sentence, so it appears in the nominative case.

The ending -a is very common for feminine nouns in Polish, although not every noun ending in -a is feminine. Here, it clearly is: pielęgniarka means female nurse.

Yes. Pielęgniarka is specifically female nurse.

The male form is pielęgniarz. In English, nurse is gender-neutral, but Polish usually marks this distinction in the noun itself.

Polish does not have articles like English the and a/an.

So pielęgniarka can mean the nurse or a nurse, and lekarstwo can mean the medicine or a medicine. The exact meaning depends on context.

In Polish, a comma is normally required before że when it introduces a subordinate clause.

So in Pielęgniarka mówi, że..., the comma separates the main clause from the clause introduced by że. This is standard Polish punctuation.

Że introduces a content clause, like English that.

So mówi, że... means says that.... Unlike English, where that is often omitted, Polish usually keeps że in this kind of sentence.

Mówi is the 3rd person singular present tense of mówić = to speak / to say.

It agrees with pielęgniarka, which is singular: the nurse says. If the subject were plural, the verb would change, for example pielęgniarki mówią = the nurses say.

Not exactly, though they are close.

Lek is a general word for medicine / drug / medication. Lekarstwo often sounds a bit more like remedy or medicine in a general sense. In many contexts they overlap, but lek is often the more standard medical term.

Also, lekarstwo is neuter singular, which is why it pairs with pomoże in singular form.

Pomoże is from pomóc, a perfective verb, and it means will help here.

Polish perfective verbs often use a form that looks present, but its meaning is future. So:

• pomaga = is helping / helps (imperfective)
• pomoże = will help (perfective)

In this sentence, the idea is a future result: the medicine will help.

Good question. Pomóc very often does take the dative when you mean help someone/something:

• pomóc pacjentowi = help the patient

But with medicines, treatments, or remedies, Polish often uses na + accusative to mean for / against a condition:

• na kaszel
• na ból gardła
• na gorączkę

So here lekarstwo pomoże na gorączkę means the medicine will help with / against fever.

Because after na in this meaning, Polish uses the accusative case.

The base form is gorączka. It is a feminine noun, and in the accusative singular it becomes gorączkę.

So:

• gorączka = nominative
• gorączkę = accusative

Yes, Polish word order is fairly flexible because grammatical relationships are often shown by endings, not just position.

The given order is neutral and natural: Pielęgniarka mówi, że lekarstwo pomoże na gorączkę.

But other orders are possible for emphasis, for example: Pielęgniarka mówi, że na gorączkę pomoże lekarstwo.

That version puts more focus on na gorączkę or on lekarstwo as the thing that will help.

Because it is in the nominative singular and the verb pomoże matches it.

In the clause że lekarstwo pomoże na gorączkę, the structure is:

• lekarstwo = subject
• pomoże = verb
• na gorączkę = prepositional phrase

So literally, the second clause is built like medicine will-help for/against fever.

In standard Polish, że is normally kept.

English can say The nurse says the medicine will help, but Polish usually says Pielęgniarka mówi, że lekarstwo pomoże na gorączkę. Omitting że would usually sound unnatural or nonstandard in this kind of sentence.