Mi prima no quiere rábano, pero sí un pepinillo pequeño.

Quiere is the 3rd person singular present tense of querer.

• yo quiero = I want
• tú quieres = you want
• él / ella quiere = he / she wants

Since the subject is mi prima = my cousin (female), Spanish uses quiere: my cousin wants / does not want.

In Spanish, standard negation usually goes directly before the conjugated verb.

So:

• quiere = she wants
• no quiere = she does not want

This is one of the most basic sentence patterns in Spanish. Unlike English, Spanish does not usually need an extra helping verb such as does.

• English: She does not want
• Spanish: No quiere

Mi is the normal possessive adjective used before a noun:

• mi prima = my cousin
• mi libro = my book

The form mi does not change for masculine or feminine singular nouns:

• mi primo = my male cousin
• mi prima = my female cousin

By contrast, mío / mía are usually used in different structures, such as:

• Es mío = It is mine
• Es mía = It is mine

So before a noun, you normally use mi, not mío / mía.

This is a very common learner question.

In Spanish, after verbs like querer, especially in negative sentences, an object can appear without an article when it is understood in a general or non-specific way.

So:

• no quiere rábano = she does not want radish / any radish

But:

• sí un pepinillo pequeño = but rather a small gherkin/pickle

Here un makes the second item sound more specific: she does not want radish, but she does want one small pickle/gherkin.

If you said no quiere un rábano, that would usually sound more like she does not want a radish / not even one radish, which is a bit more specific.

Pero sí creates a strong contrast.

The pattern is:

• no ..., pero sí ... = not ..., but yes ... / but rather ...

So in this sentence:

• no quiere rábano, pero sí un pepinillo pequeño

the idea is:

• she does not want radish,
• but she does want a small pickle/gherkin.

The sí here is not just the basic word yes in isolation. It is being used to affirm the second part in contrast to the first.

The accent mark is important because it distinguishes sí from si.

• sí = yes / an affirmative word
• si = if

So here it must be sí, because it is affirming the second idea:

• pero sí = but yes / but indeed

This is a meaning difference, not just a pronunciation detail.

In Spanish, adjectives usually come after the noun.

So the most neutral order is:

• un pepinillo pequeño = a small pickle/gherkin

That is the standard descriptive order.

If you put the adjective before the noun, as in un pequeño pepinillo, it can sound a bit more subjective, literary, or expressive depending on context. Often the version after the noun is the safest and most literal when you are simply describing size.

So here pepinillo pequeño is the straightforward way to say that the pickle/gherkin is small.

In Spain:

• pepino usually means cucumber
• pepinillo usually means a small cucumber, often a gherkin / pickled cucumber

So pepinillo is not just a random smaller form. It often refers to the specific food item that in English may be translated as gherkin or sometimes pickle, depending on context.

That is why pepinillo and rábano are not interchangeable vocabulary items.

Because these are things, not people.

Spanish often uses the personal a before a specific human direct object:

• Veo a mi prima = I see my cousin

But with non-person objects, you normally do not use a:

• quiere rábano
• quiere un pepinillo pequeño

So there is no a here because she is wanting food items, not a person.

A simple pronunciation guide:

• rábano ≈ RA-ba-no
• pepinillo ≈ pe-pi-NEE-yo in most of Spain

A few useful notes:

• rábano has a written accent because the stress falls on the first syllable: RÁ-ba-no
• In most of Spain today, ll is pronounced like y, so pepinillo sounds roughly like pepiniyo
• The r in rábano is a single tapped r, not a strong rolled rr

So the main stress points are:

• RÁbano
• pepiNIllo

Yes. A comma before pero is very common and natural when it links two contrasting parts of a sentence.

So:

• Mi prima no quiere rábano, pero sí un pepinillo pequeño.

This is standard punctuation because pero introduces a contrast: not this, but that.

Even in short sentences, this comma is often used.