Ta bransoletka pasuje do naszyjnika, który kupiłam w małym sklepie obok rynku.

Because bransoletka is a feminine noun in Polish, and the demonstrative this has to agree with the noun in gender, number, and case.

So in the nominative singular:

• ten = masculine
• ta = feminine
• to = neuter

Since bransoletka is feminine, you say ta bransoletka.

The verb pasować do means to match / to go with / to suit.

It is a fixed pattern:

• pasować do + genitive

So:

• bransoletka pasuje do naszyjnika = the bracelet matches the necklace

You cannot normally just say pasuje naszyjnik here, because pasować in this meaning requires do.

Because the preposition do requires the genitive case.

The dictionary form is:

• naszyjnik = necklace

But after do, it changes to the genitive:

• do naszyjnika

This is very common in Polish. Many prepositions force a specific case, and do almost always takes the genitive.

Który here is a relative pronoun, meaning which / that.

It introduces the clause:

• który kupiłam w małym sklepie obok rynku

This clause describes naszyjnika.

So structurally:

• naszyjnika = the necklace
• który kupiłam... = which I bought...

In English, you might say the necklace that I bought... or the necklace which I bought...

Because który is the subject of the relative clause.

Inside the clause:

• który kupiłam literally means which I bought

Even though English puts which/that after bought, Polish grammar treats który according to its role in the relative clause.

Here, the underlying idea is:

• Kupiłam naszyjnik.
• Naszyjnik is the direct object of kupiłam.

So you may expect an accusative form, but because naszyjnik is masculine inanimate, its accusative singular is the same as the nominative singular:

• nominative: który
• accusative masculine inanimate: który

So the form stays który.

If it referred to a masculine animate noun, you would often see a different form, such as którego.

Because Polish past tense agrees with the gender of the speaker.

• kupiłam = I bought said by a woman
• kupiłem = I bought said by a man

So this sentence tells you that the speaker is female.

Yes, but he would say:

• Ta bransoletka pasuje do naszyjnika, który kupiłem w małym sklepie obok rynku.

The only change is:

• kupiłam → kupiłem

Everything else can stay the same.

Because after w meaning in, Polish usually uses the locative case.

Dictionary forms:

• mały sklep = small shop

After w, they change:

• w małym sklepie = in a small shop

Both the adjective and the noun change, because adjectives must agree with nouns in gender, number, and case.

Because obok takes the genitive case.

So:

• rynek = market square
• obok rynku = next to / beside the market square

This is another example of a preposition controlling case, just like do.

Often rynek means the market square in a town or city, especially in Central European contexts.

Depending on context, it can also mean market in a broader sense, but in a sentence like:

• mały sklep obok rynku

many learners should understand it as:

• a small shop next to the market square / main square

So it is often more location-like than the English word market might suggest.

Because in Polish, a relative clause introduced by words like który is normally separated by a comma.

So:

• naszyjnika, który kupiłam...

This is standard Polish punctuation.

In English, relative clauses are not always punctuated the same way, so this can feel different to English speakers.

Yes, Polish word order is fairly flexible, though some versions sound more natural than others.

The original:

• Ta bransoletka pasuje do naszyjnika, który kupiłam w małym sklepie obok rynku.

is natural and neutral.

You could move things for emphasis, for example:

• Ta bransoletka do naszyjnika pasuje.
• Naszyjnik, który kupiłam w małym sklepie obok rynku, pasuje do tej bransoletki.

But these may shift the emphasis or sound less neutral. For learners, the original order is a very good model.

In English, you can often say:

• the necklace I bought

without that/which.

In Polish, you normally must keep the relative pronoun:

• naszyjnika, który kupiłam...

Leaving out który would sound ungrammatical.

So this is an important difference from English.

No. Pasować is used quite broadly.

It can mean:

• to match: Ta bransoletka pasuje do naszyjnika.
• to suit: Ta sukienka ci pasuje. = This dress suits you.
• to fit: Ten klucz pasuje do zamka. = This key fits the lock.

So the core idea is something like to go well with / to fit appropriately.

It is in the nominative case, because it is the subject of the sentence.

You can see the main structure like this:

• Ta bransoletka = subject
• pasuje = verb
• do naszyjnika = prepositional phrase

So ta bransoletka is the thing that matches.

This sentence is a nice example of several cases at once:

• Nominative: ta bransoletka
  the subject

• Genitive: do naszyjnika, obok rynku
  required by do and obok

• Accusative: który
  as the direct object inside the relative clause, though for a masculine inanimate noun it looks the same as nominative

• Locative: w małym sklepie
  required by w when it means in

So even one short sentence can contain a lot of case information.