Les botes blanques no són les que busco; jo volia unes sabatilles negres.

Because botes is a feminine plural noun in Catalan, so it takes the feminine plural article les.

• la bota = the boot
• les botes = the boots

The adjective also has to match in gender and number, which is why you get blanques.

Catalan adjectives usually agree with the noun they describe in gender and number.

Here, botes is feminine plural, so:

• blanc = white, masculine singular
• blanca = feminine singular
• blancs = masculine plural
• blanques = feminine plural

So botes blanques means white boots, with full agreement.

Catalan, like Spanish, often distinguishes between ser and estar.

Here, són comes from ser, because the sentence is identifying something:

• No són les que busco = They are not the ones I’m looking for

This is about identity, not temporary state or location, so ser is the correct verb.

Because the subject is plural: les botes blanques.

• és = is
• són = are

So:

• La bota blanca no és... = The white boot is not...
• Les botes blanques no són... = The white boots are not...

That les means the ones. It refers back to a feminine plural noun that is understood from context, here botes.

So:

• les que busco = the ones that I’m looking for

You can think of it as a shortened version of something like:

• les botes que busco

But Catalan often uses article + que to mean the one(s) that...

Examples:

• el que vull = the one / what I want
• la que conec = the one I know
• les que busco = the ones I’m looking for

Here que is a relative pronoun, meaning that or which.

So:

• les que busco = the ones that I’m looking for

It links les (the ones) to the clause busco (I am looking for).

Yes. Catalan often leaves out subject pronouns because the verb ending already shows who the subject is.

So volia already means I wanted. You could say:

• Volia unes sabatilles negres

Adding jo gives emphasis or contrast:

• jo volia... = I wanted... / as for me, I wanted...

In this sentence, jo helps create a contrast with the first clause:

• These white boots are not what I’m looking for; I wanted black sneakers.

Volia is the imperfect of voler (to want). In this kind of context, the imperfect often expresses:

• an intention
• a desire
• something the speaker had in mind
• a polite way of saying what they wanted

So jo volia unes sabatilles negres sounds natural in a shop or selection context: I wanted / I was after some black sneakers.

If you used vaig voler, it would sound more like a completed past event: I wanted at some specific moment. That is usually less natural here.

Because the speaker is talking about some black sneakers, not a specific already-identified pair.

• unes sabatilles negres = some black sneakers / a pair of black sneakers
• les sabatilles negres = the black sneakers

So unes is the feminine plural indefinite article, matching sabatilles.

Not always. Sabatilles can mean different kinds of light footwear depending on region and context.

It may mean things like:

• sneakers / trainers
• slippers
• other light shoes

In this sentence, because they are being contrasted with botes and described by color in a shopping-like context, sneakers/trainers is a very natural interpretation.

In Catalan, adjectives usually come after the noun, especially for basic descriptive adjectives like colors.

So:

• unes sabatilles negres = black sneakers
• literally: some sneakers black

This is the normal word order in Catalan.

Because the two verbs refer to slightly different time perspectives.

• no són les que busco = they are not the ones I’m looking for now
• jo volia unes sabatilles negres = I wanted / I had in mind some black sneakers

So the speaker is describing a current search with busco, while volia refers to what they had wanted or intended.

This mix of tenses is completely natural.

Yes. The semicolon is just punctuation linking two closely related clauses.

You could also write:

• Les botes blanques no són les que busco. Jo volia unes sabatilles negres.

The semicolon gives a slightly smoother connection between the two ideas, but the meaning stays the same.