Eu não gosto de comprar nada sem que a vendedora explique a garantia.

Because gostar normally takes the preposition de before a verb or noun.

• gostar de + infinitive = to like doing something
• gostar de + noun = to like something

So:

• Eu gosto de comprar = I like to buy / I like buying
• Eu gosto de café = I like coffee

This is a very common pattern in Portuguese, and the de should not be omitted in standard usage.

Portuguese commonly uses negative concord, which means multiple negative words can appear together in the same sentence without canceling each other out.

So:

• Eu não gosto de comprar nada = I don’t like buying anything

Literally, it may look like I don’t like to buy nothing, but in Portuguese this is the normal way to say I don’t like buying anything.

Other examples:

• Não vi ninguém = I didn’t see anyone
• Não quero nunca mais isso = I never want that again

Sem que means without ...ing / unless / without the fact that depending on context.

In this sentence:

• sem que a vendedora explique a garantia
  = without the saleswoman explaining the warranty

It introduces a clause after sem. When sem is followed by a whole clause with its own subject, Portuguese often uses sem que.

Compare:

• Sem explicar a garantia = without explaining the warranty
• Sem que a vendedora explique a garantia = without the saleswoman explaining the warranty

The second one is needed here because the clause has its own subject: a vendedora.

Because after sem que, Portuguese usually uses the subjunctive.

So:

• explica = present indicative
• explique = present subjunctive

The subjunctive is common after expressions involving uncertainty, condition, desire, emotion, or something not yet realized. Here, the explanation is something required before the purchase happens, so Portuguese uses the subjunctive:

• sem que a vendedora explique...

This is a very useful pattern to remember:

• antes que + subjunctive
• para que + subjunctive
• sem que + subjunctive

Yes, but not in exactly the same way.

You could say:

• Eu não gosto de comprar nada sem a vendedora explicar a garantia.

This is understandable and natural in many contexts, especially in spoken Brazilian Portuguese.

However, sem que a vendedora explique is a bit more formally structured and clearly uses a subordinate clause with the subjunctive.

A simpler alternative is:

• Eu não gosto de comprar nada sem explicação da garantia.
• Eu não gosto de comprar nada sem que me expliquem a garantia.

Each version has a slightly different tone, but the original sentence is completely correct and natural.

Portuguese often uses the definite article before nouns much more than English does.

So a vendedora here means:

• the saleswoman
• or in context, simply the salesperson / sales clerk

Using the article sounds natural because we are referring to the relevant person in the situation.

In many cases, Portuguese prefers the article where English would not:

• Falei com o professor = I spoke to the teacher / I spoke to my teacher
• A menina chegou = The girl arrived

Yes. Vendedora is feminine.

• o vendedor = male salesperson / salesman
• a vendedora = female salesperson / saleswoman

In real-life Brazilian Portuguese, people may also use more general terms depending on the setting, such as:

• atendente = clerk, attendant
• funcionária = female employee

But vendedora is perfectly normal if the person is specifically selling something and is female.

Again, Portuguese often uses the definite article where English might not.

• explicar a garantia = explain the warranty

This usually refers to the warranty for the product being discussed. The article makes it sound specific and natural.

Compare:

• explicar garantia sounds incomplete or unnatural in standard Portuguese
• explicar a garantia sounds normal

Garantia usually means warranty or guarantee, depending on context.

In a shopping context, it most often means warranty:

• how long the product is covered
• what problems are included
• whether repairs or replacement are possible

So here it likely means the speaker does not like buying something unless the salesperson explains the warranty terms.

This is the normal Portuguese structure.

Breakdown:

• Eu = I
• não gosto = do not like
• de comprar = to buy / buying
• nada = anything
• sem que... = without...

So the sentence builds naturally as:

1. subject: Eu
2. negated verb: não gosto
3. preposition + infinitive: de comprar
4. object under negation: nada
5. condition: sem que...

Portuguese word order is often similar to English, but negative items like nada, ninguém, and nunca often follow this negative structure.

No. Portuguese often drops subject pronouns when the verb already makes the subject clear.

So you could also say:

• Não gosto de comprar nada sem que a vendedora explique a garantia.

This is very natural.

Including Eu can add emphasis, contrast, or clarity:

• Eu não gosto de comprar nada... = As for me, I don’t like buying anything...

Not in the same structure.

With não, the most natural word is nada:

• Eu não gosto de comprar nada... = I don’t like buying anything...

If you use alguma coisa, the sentence usually becomes awkward or changes meaning.

Natural choices include:

• não gosto de comprar nada
• gosto de comprar alguma coisa = I like to buy something

So after a negative verb, nada is the normal choice.

Good question. Portuguese often leaves out an indirect object like to me when it is obvious from context.

So:

• explique a garantia = explain the warranty
• me explique a garantia = explain the warranty to me

Both can work, but the original sentence is perfectly fine because it is already clear who needs the explanation: the speaker.

If you want to make it more explicit, you could say:

• Eu não gosto de comprar nada sem que a vendedora me explique a garantia.

That sounds very natural too.

It is natural and correct, but a little more careful or polished than casual everyday speech.

A Brazilian speaker might also say:

• Eu não gosto de comprar nada sem a vendedora me explicar a garantia.
• Eu não compro nada sem a vendedora explicar a garantia.
• Eu não gosto de comprar sem saber como funciona a garantia.

The original sentence is absolutely fine, especially in writing or in more deliberate speech. It just uses a structure, sem que + subjunctive, that sounds slightly more formal than the simplest conversational version.