L’addetto del check-in controlla il passaporto e la conferma della prenotazione.

Because il becomes l’ before a singular noun that starts with a vowel.

• il + addetto → l’addetto

This is called elision. Italian does this to make pronunciation smoother.

A few similar examples:

• l’amico
• l’albergo
• l’aeroporto

So l’addetto still means the staff member / the agent, just with the shortened article.

Addetto means a person assigned to a particular job or area, such as an attendant, agent, staff member, or employee in charge.

In this sentence, l’addetto del check-in is the person working at check-in, so in natural English you might think of:

• the check-in agent
• the check-in attendant
• the staff member at check-in

It is a very common word in formal or service-related contexts:

• addetto alla reception = reception staff member
• addetto alla sicurezza = security staff member

Del is the contraction of di + il:

• di = of
• il = the
• di + il = del

So del check-in literally means of the check-in.

In natural English, we would usually not translate it word for word. Instead, l’addetto del check-in is understood as:

• the check-in agent
• the person at check-in

This kind of di + article structure is very common in Italian.

Even though check-in is an English word, Italian still treats it like a noun that needs grammatical gender and an article.

Here it is treated as masculine singular, so:

• il check-in
• del check-in

This is very common with borrowed words in Italian. Many English loanwords are treated as masculine by default.

Also, borrowed nouns usually do not change in the plural:

• il check-in
• i check-in (if needed)

Controlla is the third person singular present tense of controllare.

The full present tense is:

• io controllo = I check
• tu controlli = you check
• lui/lei controlla = he/she checks
• noi controlliamo = we check
• voi controllate = you all check
• loro controllano = they check

So in this sentence, controlla means checks.

Usually, no. This is an important false friend.

In Italian, controllare often means:

• to check
• to inspect
• to verify

So here:

• controlla il passaporto = checks the passport

If you want to say to control in the sense of to dominate / regulate / keep under control, Italian may use other expressions depending on context, such as:

• controllare sometimes can mean to control
• but very often learners should first remember its common meaning: to check

In travel and document contexts, controllare is almost always to check.

Because Italian nouns have grammatical gender.

• passaporto is masculine → il passaporto
• conferma is feminine → la conferma

The article has to agree with the noun:

• masculine singular: il / l’
• feminine singular: la / l’

So the sentence uses the correct articles for each noun.

In Italian, it is normal to repeat the article before each noun.

So:

• il passaporto e la conferma

is more natural and correct than leaving the second article out.

Italian generally likes clearer agreement, especially when the nouns have different genders:

• il passaporto
• la conferma

Repeating the article makes the structure neat and easy to understand.

It means confirmation of the booking/reservation.

Breakdown:

• conferma = confirmation
• della = di + la = of the
• prenotazione = reservation / booking

So literally:

• la conferma della prenotazione = the confirmation of the reservation

In travel English, this often corresponds to:

• the booking confirmation
• the reservation confirmation

Because della is the contraction of di + la:

• di = of
• la = the
• di + la = della

Since prenotazione is feminine singular, it takes la, and after di that becomes della.

Compare:

• del passaporto = of the passport
• della prenotazione = of the reservation
• dell’albergo = of the hotel

Yes. Prenotazione can mean both reservation and booking, depending on context.

Examples:

• prenotazione dell’hotel = hotel booking
• prenotazione del volo = flight booking
• prenotazione al ristorante = restaurant reservation

In this airport-style sentence, la conferma della prenotazione is very naturally understood as the booking confirmation.

They are both direct objects of the verb controlla.

The structure is:

• L’addetto del check-in = subject
• controlla = verb
• il passaporto e la conferma della prenotazione = direct objects

So the agent checks two things:

1. il passaporto
2. la conferma della prenotazione

Because Italian usually does not need subject pronouns when the verb ending already shows the person.

Here, controlla already tells us the subject is:

• he/she/it checks

And the noun phrase L’addetto del check-in clearly tells us who is doing the action.

So adding lui would usually be unnecessary:

• L’addetto del check-in controlla... = perfectly normal

Italian often leaves out subject pronouns unless they are needed for emphasis or contrast.

A simple pronunciation guide is:

• l’addetto ≈ lahd-DET-toh
• del ≈ del
• check-in ≈ close to the English check-in

A few points:

• The dd in addetto is pronounced clearly, with a stronger consonant than in English.
• The stress is on -det-: ad-DÈT-to
• L’addetto links smoothly together because of the elision.

A rough full pronunciation:

lad-DET-to del check-in con-TROL-la eel passa-POR-to eh la con-FER-ma DEL-la preno-ta-TSYO-ne

Yes. Italian often allows small variations.

For example, you might also hear:

• L’addetto al check-in controlla il passaporto e la conferma della prenotazione.

Here al check-in means at check-in / assigned to check-in.

Both are understandable, but the sentence you were given is perfectly interpretable as referring to the check-in staff member. For a learner, the main useful points are still:

• addetto = staff member/agent
• controlla = checks
• prenotazione = booking/reservation
• del / della = contractions of di + article