Ta bluzka pasuje do mojego kapelusza, ale nie do brązowego paska.

Because bluzka is a feminine noun in Polish.

Polish demonstratives must agree with the gender of the noun:

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

So:

• ta bluzka = this blouse/top
• ten kapelusz = this hat
• to okno = this window

Here, bluzka is feminine, so ta is the correct form.

Bluzka usually means blouse or women’s top.

Depending on context, English might translate it as:

• blouse
• top
• sometimes a light shirt-like garment for a woman

So in this sentence, Ta bluzka is most naturally This blouse or This top.

Pasować do means to match, to go well with, or to suit something.

So:

• Ta bluzka pasuje do mojego kapelusza = This blouse matches my hat
• literally, something like This blouse suits/fits with my hat

Be careful: Polish often uses pasować do + Genitive where English uses match/go with.

Also, pasować can have other meanings in other contexts, for example:

• Ta sukienka mi pasuje = This dress suits me / fits me
• Ten termin mi pasuje = That time works for me

So the meaning depends on what comes after it.

Because the verb pattern here is:

• pasować do + Genitive

The preposition do is required when you mean match/go with.

Examples:

• Ta koszula pasuje do spodni = This shirt goes with the trousers
• Buty pasują do płaszcza = The shoes match the coat

So pasuje do mojego kapelusza is not random wording; it follows a normal Polish grammar pattern.

Because after do, Polish uses the Genitive case.

The dictionary forms are:

• mój kapelusz = my hat
• after do → do mojego kapelusza

Both the possessive adjective and the noun change:

• mój → mojego
• kapelusz → kapelusza

So:

• do mojego kapelusza = to/with my hat in the sense required by pasować do

This is one of the most important things to notice in the sentence: do triggers the Genitive.

For the same reason: do requires the Genitive.

The basic form is:

• brązowy pasek = a brown belt / the brown belt

After do, both words change to Genitive:

• brązowy → brązowego
• pasek → paska

So:

• do brązowego paska = with/to the brown belt in the grammatical sense used after pasuje do

The adjective must agree with the noun in:

• gender
• number
• case

Since pasek is masculine singular and here it is in the Genitive, brązowego is the matching adjective form.

Because Polish normally repeats the preposition when contrasting two things.

So the structure is:

• pasuje do mojego kapelusza, ale nie do brązowego paska

Literally:

• matches my hat, but not my brown belt

In English, we often do the same:

• It goes with my hat, but not with my brown belt
• or more naturally, ...but not my brown belt

Polish strongly prefers keeping do here. Leaving it out would sound incomplete or unnatural in standard Polish.

Because nie negates the whole prepositional phrase:

• nie do brązowego paska = not with the brown belt

Polish often places nie directly before the part being negated.

Here the contrast is:

• do mojego kapelusza
• nie do brązowego paska

So the sentence means the blouse matches one item, but not the other.

Bluzka is in the Nominative singular because it is the subject of the sentence.

The sentence structure is:

• Ta bluzka = subject
• pasuje = verb
• do mojego kapelusza = prepositional phrase
• ale nie do brązowego paska = contrasting prepositional phrase

So:

• bluzka stays in its basic subject form
• the nouns after do change to Genitive

Not in standard Polish for this meaning.

If you want to say matches/goes with, the normal pattern is:

• pasować do + Genitive

So the correct sentence is:

• Ta bluzka pasuje do mojego kapelusza

Using z here would sound wrong for this meaning.

A learner mistake is to translate English with too directly. In Polish, the idiomatic construction is do, not z.

It is just subject-verb agreement.

• pasuje = it matches / suits for a singular subject
• pasują = they match / suit for a plural subject

Here the subject is singular:

• Ta bluzka = This blouse
• so we use pasuje

Compare:

• Ta bluzka pasuje do kapelusza = This blouse matches the hat
• Te bluzki pasują do kapelusza = These blouses match the hat

The given word order is the most natural and neutral:

• Ta bluzka pasuje do mojego kapelusza, ale nie do brązowego paska.

Polish word order is more flexible than English, so other orders are possible for emphasis. For example:

• Do mojego kapelusza ta bluzka pasuje, ale nie do brązowego paska.

That sounds more marked and emphasizes the contrast.

For learners, the original order is the safest choice because it is clear, natural, and neutral.

Yes, in this sentence pasek most naturally means belt.

The word can have other meanings in other contexts, such as:

• a strip
• a stripe
• a bar
• a small belt/strap

But with clothing vocabulary like bluzka and kapelusz, brązowego paska is best understood as a brown belt.