Pasagerul primește numărul de referință.

Because Romanian usually puts the definite article at the end of the noun, not before it.

• pasager = a passenger
• pasagerul = the passenger

For a masculine singular noun like pasager, the definite article is often -ul.

Numărul means the number.

So the phrase numărul de referință is literally the number of reference, which corresponds to English the reference number.

Romanian often makes the main noun definite in this kind of expression:

• număr = number
• numărul = the number
• numărul de referință = the reference number

Romanian usually does not use a separate word like English the. Instead, it attaches the definite article to the noun itself.

In this sentence:

• pasagerul = the passenger
• numărul = the number

This is one of the most noticeable differences between English and Romanian.

Primește is the 3rd person singular present tense form of the verb a primi, meaning to receive.

So:

• eu primesc = I receive
• tu primești = you receive
• el/ea primește = he/she receives

Here it matches pasagerul because pasagerul is singular: the passenger receives.

That is just the standard present-tense form of a primi in Romanian.

The verb belongs to a common pattern where:

• eu primesc
• tu primești
• el/ea primește
• noi primim
• voi primiți
• ei/ele primesc

So primește is not irregular in a strange way; it follows a normal Romanian conjugation pattern.

De referință literally means of reference, but in natural English it is usually translated as reference.

So:

• numărul de referință = the reference number

Romanian often uses de + noun where English might use a noun directly as an adjective.

Compare:

• număr de telefon = telephone number
• carte de istorie = history book
• număr de referință = reference number

Yes, functionally it is describing numărul, even though it is not a simple adjective form.

In English, reference in reference number behaves like a noun used adjectivally. Romanian often expresses that idea with de + noun:

• numărul = the main noun
• de referință = a describing phrase attached to it

So it works a bit like an adjective in meaning, even though grammatically it is a prepositional phrase.

In this sentence, the normal Romanian word order helps:

• Pasagerul = subject
• primește = verb
• numărul de referință = direct object

So the structure is:

Subject + Verb + Object

Romanian can sometimes change word order for emphasis, but this sentence uses the most neutral and common order.

In Romanian, the nominative and accusative are often identical in form, especially for nouns like these.

So:

• numărul can be nominative
• numărul can also be accusative

You usually understand the role from:

• word order
• the verb
• context

So there is no extra visible ending here to show direct object.

• pasager is masculine
• număr is neuter
• referință is feminine

A useful thing to know: Romanian neuter nouns behave like:

• masculine in the singular
• feminine in the plural

So in the singular, număr takes endings like a masculine noun:

• un număr = a number
• numărul = the number

The main special letters here are:

• ș = sh sound, like in ship
• ț = ts sound, like in cats
• ă = a short central vowel, something like the a in sofa

So:

• primește has ș = pri-mesh-te
• referință has ț and ă
• numărul has ă

You do not need a perfect English equivalent for ă right away; just aim for a short, relaxed vowel.

Yes, Romanian allows more flexibility than English, but the basic, neutral order here is the best one for learners:

Pasagerul primește numărul de referință.

That is the standard Subject + Verb + Object order.

Other orders are possible in special contexts for emphasis, contrast, or style, but they are not the default form you should start with.

Because this sentence is definite, not indefinite.

It is talking about:

• the passenger
• the reference number

If you wanted an indefinite version, you could say:

• Un pasager primește un număr de referință.
• A passenger receives a reference number.

So:

• un pasager = a passenger
• pasagerul = the passenger
• un număr = a number
• numărul = the number