Aggiorno la rubrica del telefono con i numeri dei nuovi colleghi.

Aggiorno is the 1st person singular present indicative of aggiornare.

So:

• aggiornare = to update
• aggiorno = I update / I’m updating

In Italian, the present tense often covers both the English simple present and present continuous, so Aggiorno can mean either:

• I update
• I am updating

The exact choice in English depends on context.

Italian usually uses the definite article more often than English.

• la rubrica = the address book / the contacts list

Here, la suggests a specific, known thing: the phone’s contact list/address book.

English might simply say I update my phone contacts, but Italian often keeps the article:

• Aggiorno la rubrica...
  literally: I update the address book...

This sounds natural in Italian.

In this sentence, rubrica means address book, contact list, or phone contacts.

So la rubrica del telefono is the list of saved contacts in the phone.

A learner should know that rubrica can have different meanings in other contexts, but here it clearly refers to contacts.

For example:

• rubrica del telefono = phone contact list
• rubrica dei contatti = contacts list

Del is a contraction of:

• di = of
• il = the

So:

• del = of the

Therefore:

• la rubrica del telefono = the phone’s address book / the address book of the phone

Italian often uses di + article where English might use an apostrophe:

• il colore della macchina = the car’s color
• la rubrica del telefono = the phone’s contact list

Con usually means with.

Here it expresses what you are using to update the contact list:

• con i numeri dei nuovi colleghi = with the numbers of the new colleagues

In natural English, you might say:

• I update my phone contacts with the new colleagues’ numbers
• I update the phone’s address book by adding the new colleagues’ numbers

So con is introducing the information being added.

Because in context, numeri is already understood to mean phone numbers.

• i numeri = the numbers
• in this context: the phone numbers

Italian often leaves out words that are obvious from context. Since the sentence is already about la rubrica del telefono, it is natural to understand numeri as contact numbers.

A more explicit version would be:

• Aggiorno la rubrica del telefono con i numeri di telefono dei nuovi colleghi.

That is correct too, but a bit more repetitive.

Dei here means of the.

It is a contraction of:

• di = of
• i = the

So:

• dei nuovi colleghi = of the new colleagues

Whole phrase:

• i numeri dei nuovi colleghi = the numbers of the new colleagues

This is a very common Italian pattern:

• il nome dei ragazzi = the boys’ name / the name of the boys
• le chiavi delle macchine = the cars’ keys / the keys of the cars

Because colleghi is masculine plural, and the adjective must agree with it.

• singular masculine: nuovo collega
• plural masculine: nuovi colleghi

So:

• dei nuovi colleghi = of the new colleagues

A useful detail: collega is a noun that can refer to both a male and a female colleague, but its plural changes depending on gender:

• colleghi = male colleagues, or a mixed group
• colleghe = female colleagues

So if all the new colleagues were female, you would say:

• dei numeri delle nuove colleghe

In Italian, many common adjectives can go either before or after the noun, but some positions are more natural depending on the adjective and nuance.

Nuovo often comes before the noun when it means new in the ordinary descriptive sense:

• nuovi colleghi = new colleagues

This is the most natural order here.

If you put it after the noun in some cases, it can sound more marked or slightly change emphasis, though with nuovo the difference depends on context.

For a learner, the safest pattern is:

• nuovo/nuovi + noun is very common

Yes, very often.

For modern everyday speech, many people would naturally say:

• Aggiorno i contatti del telefono...
• Aggiorno i contatti sul telefono...

That would mean I update the phone contacts.

The difference is roughly:

• rubrica = address book / contacts list as a whole
• contatti = contacts

Both are correct, but contatti may sound a bit more modern and direct in many situations.

Italian often leaves out possessives when ownership is obvious from context.

So instead of saying:

• Aggiorno la mia rubrica del telefono

Italian can simply say:

• Aggiorno la rubrica del telefono

and it is understood that it is my phone’s contact list, unless context suggests otherwise.

English uses possessives more often, but Italian does not always need them.

Yes, the word order is natural:

• Aggiorno la rubrica del telefono con i numeri dei nuovi colleghi.

It follows a common pattern:

• verb + object + extra information

You could change the order for emphasis, but the original is the most neutral and standard.

For example:

• Con i numeri dei nuovi colleghi, aggiorno la rubrica del telefono.

This is grammatically correct, but it puts emphasis on with the new colleagues’ numbers.

The original sentence is the most straightforward version for normal use.