Na urodziny dostałam delikatny naszyjnik, a moja siostra dostała kolczyki.

In Polish, na + accusative is often used to mean for in the sense of an occasion or event.

So:

• na urodziny = for a birthday / as a birthday gift
• similar patterns:
  • na ślub = for a wedding
  • na imieniny = for a name day
  • na Boże Narodzenie = for Christmas

Here, urodziny is plural in form, even though in English we often think of birthday as singular.

In Polish, urodziny is normally used in the plural. That is just the standard word for birthday.

So you say:

• Mam urodziny w maju. = My birthday is in May.
• Prezent na urodziny = a birthday present

This is similar to some English words that are plural in form but refer to one event or concept, like thanks or congratulations.

These are past tense forms of dostać = to receive / to get.

Polish past tense changes according to gender and number.

Here:

• dostałam = I received spoken by a woman
• dostała = she received

More forms of dostać in the past:

• dostałem = I received, said by a man
• dostałaś = you received, said to a woman
• dostał = he received
• dostali / dostały = they received

So this sentence tells us the speaker is female.

Dostać is the perfective verb, and dostawać is the imperfective partner.

• dostać = to receive/get, seen as a completed event
• dostawać = to be receiving / to receive repeatedly / habitually

In this sentence, the speaker is talking about one completed event, so dostałam and dostała are natural.

Compare:

• Na urodziny dostałam naszyjnik. = I got a necklace for my birthday.
• Zawsze dostawałam książki na urodziny. = I used to get books for my birthday.

Because the adjective must agree with the noun in gender, number, and case.

• naszyjnik = masculine singular
• here it is in the accusative, but for an inanimate masculine noun, the accusative looks the same as the nominative
• so delikatny also stays in the masculine singular form

That gives:

• delikatny naszyjnik = a delicate necklace

If the noun changed, the adjective would change too:

• delikatna bransoletka = a delicate bracelet
• delikatne kolczyki = delicate earrings

Because kolczyki usually means earrings, which naturally come as a pair, so Polish normally uses the plural.

• naszyjnik = necklace, usually one item
• kolczyki = earrings, usually plural

Even if English sometimes says a pair of earrings, Polish often simply says kolczyki.

Polish often allows possessive words like my, your, his to be omitted when the meaning is obvious. But they can also be included for clarity or emphasis.

So:

• moja siostra = my sister
• siostra could also work in some contexts

Using moja here helps clearly contrast the two people:

• I got a necklace,
• my sister got earrings.

It sounds natural and clear.

Polish often drops subject pronouns because the verb ending already shows who the subject is.

• dostałam already tells us I and also that the speaker is female
• dostała tells us she

So Polish usually says:

• Dostałam prezent.

rather than:

• Ja dostałam prezent.

Adding ja is possible, but it usually adds emphasis or contrast.

Not exactly.

• i = and
• a = and/but, often used to connect two related ideas with a slight contrast

In this sentence, a works well because the speaker and the sister received different things:

• I got a delicate necklace,
• while / and my sister got earrings.

So a is very natural here. It is softer than a strong but, but it does suggest contrast.

Yes. Polish word order is fairly flexible, though some versions sound more natural depending on emphasis.

The given sentence is neutral and natural:

• Na urodziny dostałam delikatny naszyjnik, a moja siostra dostała kolczyki.

You could also say:

• Dostałam na urodziny delikatny naszyjnik, a moja siostra dostała kolczyki.

This is also natural. The difference is mainly in emphasis:

• starting with Na urodziny highlights the occasion
• starting with Dostałam highlights the action

They are in the accusative, because they are the direct objects of dostałam / dostała.

• dostać coś = to receive something

So:

• dostałam naszyjnik
• dostała kolczyki

However, the forms look unchanged here:

• naszyjnik: masculine inanimate, so accusative = nominative
• kolczyki: non-masculine-personal plural, so accusative = nominative

That is why they look like dictionary forms.

Yes. In many contexts, both are possible.

• dostać often means to get in everyday English
• in more formal or careful English, to receive may fit better

So this sentence could be understood with either idea. Polish dostać is very common and natural in everyday speech.

Examples:

• Dostałem list. = I got / received a letter.
• Dostała prezent. = She got / received a present.