Agentul constatator verifică numărul de înmatriculare.

Because -ul is the Romanian definite article attached to the end of a masculine singular noun.

• agent = an agent / agent
• agentul = the agent

Romanian usually puts the definite article at the end of the noun, unlike English, which uses a separate word (the).

This is a fairly formal, legal-administrative expression. It refers to the officer/official who establishes or records an offense, violation, or contravention.

A very natural English rendering depends on context:

• the inspecting officer
• the reporting officer
• the officer who establishes the violation
• the attending officer (sometimes, depending on context)

So agent here does not mean a secret agent. It means an official / officer / authorized agent.

Because in Romanian, adjectives usually come after the noun.

So:

• agentul constatator = literally the agent establishing / ascertaining

That word order is normal in Romanian. English often prefers adjective + noun, but Romanian commonly uses noun + adjective.

Also, agent constatator is a fixed legal phrase, so learners will often meet it in exactly this order.

Here it is functioning as an adjective modifying agentul.

It comes from the verb a constata, meaning to ascertain, to establish, to determine officially, or to note/find.

So:

• agent constatator = ascertaining/reporting officer, literally officer that establishes/finds officially

In legal Romanian, this combination is so common that it can feel almost like a set title.

Verifică is the 3rd person singular present tense of a verifica (to check / to verify).

So it can mean:

• he checks
• she checks
• it checks
• the officer checks

In this sentence, the subject is agentul constatator, so:

• Agentul constatator verifică... = The officer checks...

Because Romanian often drops subject pronouns when they are not needed. The verb ending already shows the person and number.

So Romanian prefers:

• Verifică = He/She checks or is checking, depending on context

You can add a pronoun for emphasis:

• El verifică = He checks
• Ea verifică = She checks

But in a normal sentence, the noun subject (agentul constatator) is enough, so no extra pronoun is needed.

For the same reason as agentul: the ending -ul marks the definite article.

• număr = a number
• numărul = the number

So:

• numărul de înmatriculare = the registration number

De înmatriculare means for registration / of registration, and it specifies what kind of number it is.

So:

• număr de înmatriculare = registration number

This is a very common Romanian structure:

• număr de telefon = telephone number
• sală de clasă = classroom
• permis de conducere = driving license

In this kind of phrase, the second noun usually stays indefinite, because it describes the type or function of the first noun.

So numărul de înmatriculare is not literally best translated word-for-word as the number of the registration, but rather as the natural English phrase the registration number.

Not exactly. Înmatriculare means registration.

So:

• număr de înmatriculare = registration number
• in everyday English, this may refer to the license plate number
• but strictly speaking, it is the number assigned in registration

If you want the physical plate itself, Romanian might use:

• plăcuță de înmatriculare = license plate / registration plate

So the sentence is about checking the number, not necessarily inspecting the metal plate itself.

Romanian present tense can often correspond to either English simple present or present continuous, depending on context.

So verifică can mean:

• checks
• is checking

In an isolated sentence like this, English usually translates it as:

• The officer checks the registration number

But in a real situation, it could also mean:

• The officer is checking the registration number

Context decides which English version sounds best.

They are important Romanian vowels.

• ă as in verifică, numărul
  This is a short central vowel, something like the a in English sofa.

• î as in înmatriculare
  This is a close central vowel, a sound English does not really have. It is said with the tongue high and central, somewhat like saying ee and uh at the same time.

A rough pronunciation guide for the sentence:

• Agentul ≈ ah-JEN-tool
• constatator ≈ kon-stah-tah-TOR
• verifică ≈ veh-ree-FEE-kuh
• numărul ≈ NOO-muh-rul
• de înmatriculare ≈ deh uhn-mah-tree-koo-LAH-reh

These are only approximations, but they help at the start.

This word order is the neutral, standard one:

• Agentul constatator = subject
• verifică = verb
• numărul de înmatriculare = object

So it follows a normal Subject–Verb–Object pattern:

• The officer checks the registration number

Romanian word order is somewhat flexible, and you may see changes for emphasis, but this version is the most straightforward and natural.

Yes, but the meaning would change.

• Agentul constatator verifică numărul de înmatriculare.
  = The officer checks the registration number.

• Un agent constatator verifică un număr de înmatriculare.
  = An officer checks a registration number.

So the articles matter a lot:

• -ul attached to the noun = the
• un / o before the noun = a / an

The original sentence sounds specific: a particular officer is checking a particular registration number.