A mi prima le encanta la avellana, pero hoy prefirió una ciruela porque estaba más madura.

Because verbs like gustar and encantar use an indirect object.

• A mi prima = to my cousin
• le = to her

In Spanish, this doubling is very common:

• A mi prima le encanta...
• literally: To my cousin, it enchants her...
• natural English: My cousin loves...

The A mi prima part clarifies or emphasizes who the feeling applies to, and le is the pronoun that normally goes with the verb.

So even though it may feel repetitive in English, in Spanish it is normal and often expected.

Because the grammatical subject of encantar here is la avellana, which is singular.

With gustar-type verbs, the thing being liked is the subject:

• Le encanta la avellana = Hazelnuts / hazelnut really please her
• Le encantan las avellanas = Hazelnuts really please her

So:

• la avellana → singular → encanta
• las avellanas → plural → encantan

Even though English says she loves hazelnuts, Spanish structures it differently.

Spanish often uses the definite article with nouns when talking about things in general, especially foods, animals, and abstract categories.

So:

• le encanta la avellana means she loves hazelnuts / the taste of hazelnut in general
• not necessarily one specific hazelnut

This is very natural in Spanish. Compare:

• Me gusta el café = I like coffee
• Le encanta la música = She loves music
• Nos gustan los perros = We like dogs

So la avellana here is a general category, not one particular nut.

Yes. Encantar works grammatically like gustar, but it expresses a stronger feeling.

• gustar = to like
• encantar = to love / to be delightful to someone

Both use the same structure:

• Me gusta el chocolate
• Me encanta el chocolate

And with other people:

• Le gusta la avellana
• Le encanta la avellana

So if you understand gustar, you can apply the same pattern to encantar.

Because preferir is a stem-changing verb, and in the preterite its third-person forms change e → i.

Preterite of preferir:

• yo preferí
• tú preferiste
• él/ella/usted prefirió
• nosotros preferimos
• vosotros preferisteis
• ellos/ellas/ustedes prefirieron

So prefirió is correct for she preferred.

This is one of the verbs where the stem change appears only in the third person forms in the preterite.

Because prefirió refers to a completed choice made today.

The sentence is talking about one specific event:

• normally she loves hazelnut
• but today she chose a plum

That is a single finished action, so Spanish uses the preterite:

• hoy prefirió una ciruela

Even though today is not over yet, Spanish can still use the preterite when the action itself is seen as completed.

Because una ciruela means a plum, that is, one plum, not a previously identified specific plum.

• una ciruela = a plum / one plum
• la ciruela = the plum

Here the sentence introduces it as the fruit she chose, so una is the natural article.

If the plum had already been mentioned, then la ciruela might be possible.

Because estaba describes the state or condition of the plum at the time of the choice.

Spanish often uses the imperfect for background description:

• how something was
• what condition it was in
• what was going on around the main action

So the structure is:

• main event: prefirió una ciruela
• background reason/description: porque estaba más madura

Using estaba suggests it was riper as a state that explains the choice.

Estuvo would sound more like a bounded, completed state, which is not the most natural choice here.

It refers to una ciruela.

That is why the adjective is:

• feminine singular: madura

Agreement:

• ciruela is feminine singular
• so the adjective must also be feminine singular

Examples:

• un plátano maduro = a ripe banana
• una ciruela madura = a ripe plum

And here:

• más madura = riper

So the meaning is that she preferred the plum because it was riper.

The sentence does not say explicitly, and that is normal.

Más madura just means riper or more ripe, but Spanish often leaves the comparison understood from context.

Possible implied meanings are:

• riper than another plum
• riper than the hazelnut option
• riper than it had been before
• simply ripe enough to be the better choice

In everyday language, people often use más + adjective without stating the full comparison if it is obvious or unimportant.

Yes. Prima means female cousin.

• primo = male cousin
• prima = female cousin

So A mi prima specifically means to my female cousin.

In English, cousin does not show gender, but Spanish does.

Yes, if the context already makes it clear who le refers to.

For example:

• Le encanta la avellana, pero hoy prefirió una ciruela...

This could be fine in conversation if everyone already knows you are talking about your cousin.

But A mi prima is useful to:

• identify the person clearly
• avoid ambiguity
• add emphasis or contrast

So in this sentence, it helps set up the topic clearly.

Either can work depending on the context.

In Spanish, la avellana is singular, but when talking generically about a food, English often prefers a plural or a mass-style translation.

So these are all possible natural translations:

• My cousin loves hazelnuts
• My cousin loves hazelnut
• My cousin really loves hazelnuts

The exact English wording depends on whether you are thinking of:

• the nut as a type of food
• the flavor
• the ingredient in general

The Spanish sentence itself is completely natural.