Mia sorella preferisce il salmone al salame, ma io li mangio entrambi volentieri.

With a singular family member, Italian usually drops the article before the possessive:

• mia sorella = my sister
• mio fratello = my brother
• mia madre = my mother

So mia sorella is the normal form here.

You often do use the article again if the family noun is:

• plural: le mie sorelle
• modified: la mia sorella maggiore
• or in some regional/colloquial usage

So in this sentence, mia sorella is exactly what you would expect.

The pattern is:

preferire X a Y = to prefer X to Y

So:

• preferisce il salmone al salame
• literally: she prefers salmon to salami

Here, al is just a + il:

• a + il = al

So:

• il salame becomes
• al salame

This is one of the most common constructions with preferire.

Italian uses the definite article much more often than English, especially with nouns referring to things in a general or category-like way.

So Italian naturally says:

• il salmone
• il salame

where English often just says:

• salmon
• salami

In this sentence, the articles make the two foods into clearly identified items being compared. This is very natural in Italian.

Yes. Italian salame is the singular form.

So:

• il salame = salami / a salami sausage
• i salami = salamis

This can feel odd to English speakers because English often uses salami as if it were singular, but in Italian salami is plural.

Yes, the subject is already clear from the verb ending:

• mangio = I eat

So io is not grammatically necessary. It is included for contrast:

• Mia sorella... ma io...
• My sister..., but I...

So io adds emphasis, something like:

• but I eat both gladly
• but as for me, I eat both gladly

This is very common in Italian: subject pronouns are often omitted unless they are being stressed or contrasted.

Li means them.

It refers back to:

• il salmone
• il salame

Since those two nouns together are masculine plural, the pronoun is li.

So:

• li mangio = I eat them

Italian object pronouns usually go before the conjugated verb, which is why it is li mangio, not mangio li.

Because it replaces two masculine nouns:

• il salmone = masculine
• il salame = masculine

Together, they become masculine plural, so the direct object pronoun is li.

For comparison:

• feminine plural noun(s) would use le
• mixed-gender groups normally use the masculine plural in Italian

So li is exactly the form you would expect here.

Entrambi means both.

It is masculine plural because it refers to two masculine things:

• il salmone
• il salame

So:

• li mangio entrambi = I eat them both

If the two things were feminine, you would use entrambe.

Examples:

• le mele e le pere? Le mangio entrambe.
• apples and pears? I eat both.

Yes, you often can.

Both are possible:

• mangio entrambi
• li mangio entrambi

The version with li makes the connection to the previously mentioned foods a little more explicit. It can sound slightly fuller or more emphatic, but both are understandable and natural depending on context.

In this sentence, li mangio entrambi works very well because the speaker is clearly referring back to the salmon and the salami.

Volentieri means something like:

• gladly
• willingly
• with pleasure

In everyday Italian, it is often used where English might use like to or don’t mind.

So:

• li mangio entrambi volentieri

means not just I eat both, but more like:

• I gladly eat both
• I’m happy to eat both
• I enjoy eating both

It adds the idea that the speaker does so happily.

There are a few things going on:

1. Li comes before the conjugated verb

   • li mangio
   • This is normal for object pronouns in Italian.

2. Entrambi comes after the verb here

   • li mangio entrambi
   • meaning I eat them both

3. Volentieri is placed at the end

   • This is a very natural position for an adverb like this.

So the order sounds smooth and idiomatic:

• li mangio entrambi volentieri

Italian word order is often more flexible than English, but this version is very standard.

Because they have different subjects.

• preferisce comes from preferire and matches mia sorella

  • (lei) preferisce = she prefers

• mangio comes from mangiare and matches io

  • (io) mangio = I eat

So the sentence contrasts:

• what my sister prefers with
• what I eat

That is why the verbs are in different persons:

• third person singular: preferisce
• first person singular: mangio

In isolation, al can have different meanings in Italian, and in food names it can sometimes mean something like with or in the style of:

• pasta al pesto
• risotto al funghi

But in this sentence, the structure with preferire makes the meaning clear:

• preferire X a Y = to prefer X to Y

So preferisce il salmone al salame can only naturally be understood as:

• she prefers salmon to salami

The verb preferire tells you how to interpret al.