A tulajdonos az üzembentartó.

Hungarian has one definite article with two forms:

• a before a consonant sound
• az before a vowel sound

So here:

• a tulajdonos = the owner
• az üzembentartó = the registered keeper / operator

Because üzembentartó starts with a vowel sound, Hungarian uses az.

In Hungarian, the verb van (to be) is usually left out in the present tense, third person singular/plural when linking two nouns or an adjective and a noun.

So:

• A tulajdonos az üzembentartó. literally: The owner the registered keeper natural English: The owner is the registered keeper.

But in other persons, the verb appears:

• Én vagyok a tulajdonos. = I am the owner.
• Te vagy az üzembentartó. = You are the registered keeper.

With both articles present, the sentence sounds like an identification: one specific person/entity is the same as another specific person/entity.

• A tulajdonos az üzembentartó. = The owner is the registered keeper. → the two roles belong to the same person/entity

If you remove the second article:

• A tulajdonos üzembentartó.

that sounds more like the owner is a registered keeper / functions as a registered keeper, which is more classificatory and less clearly identity-based.

So the version with az is the more natural one if you mean that the owner and the registered keeper are the same person.

Yes, you could say:

• Az üzembentartó a tulajdonos.

That would still mean roughly the same thing: The registered keeper is the owner.

The difference is mainly in topic/emphasis:

• A tulajdonos az üzembentartó. → talking about the owner, and saying who that is
• Az üzembentartó a tulajdonos. → talking about the registered keeper, and identifying them as the owner

So the basic relationship stays the same, but the starting point of the sentence changes.

Tulajdonos means owner or proprietor.

It refers to the person or entity that legally owns something. In everyday and legal Hungarian, it is a normal, very common word.

Examples:

• A ház tulajdonosa = the owner of the house
• Az autó tulajdonosa = the owner of the car

In your sentence, it is in its basic dictionary form, with no extra case ending.

Üzembentartó is a more specialized word, often used in official, legal, or vehicle-related contexts.

It refers to the person or entity that keeps something in operation or is the registered keeper/operator. In car-related usage, it often means the person officially responsible for the vehicle’s operation, who may or may not be the owner.

So:

• tulajdonos = owner
• üzembentartó = registered keeper / operator

These can be the same person, and your sentence says that in this case, they are.

Yes, it is one word, and it is a compound.

It comes from the idea of üzemben tart = to keep in operation / keep running.

Very roughly:

• üzem = operation, plant, functioning
• -ben = in
• tartó = keeper / one who keeps

So üzembentartó is literally something like the one who keeps it in operation.

Learners do not need to analyze every part each time, but it helps explain why the word is long and why it has a formal/technical flavor.

Because both nouns are in the nominative form, the basic dictionary form.

This is a simple equational sentence:

• A tulajdonos = subject/topic
• az üzembentartó = predicate noun

Hungarian does not need a special ending here. English also uses plain forms in this kind of sentence:

• The owner is the registered keeper.

So no extra case ending is needed on either noun.

It sounds somewhat official or administrative, mainly because of the word üzembentartó.

The grammar itself is completely normal, but the vocabulary suggests a context like:

• vehicle registration
• legal documents
• insurance paperwork
• official records

A Hungarian speaker would immediately recognize üzembentartó as a more formal term than ordinary everyday vocabulary.

A rough English-friendly guide:

• tulajdonos ≈ too-lawdyo-nosh
• üzembentartó ≈ ue-zehm-ben-tar-toe

A few useful pronunciation notes:

• s in Hungarian is pronounced like English sh
  • so tulajdonos ends with -nosh
• sz would be the plain English s, but there is no sz here
• ó is a long o
• ü is a front rounded vowel, which English does not really have; approximate it as something between ee and oo

If you want to sound more natural, keep the stress on the first syllable of each word:

• TU-lajdonos
• Ü-zembentartó

It can refer to either.

Hungarian often uses these nouns for:

• a person
• a company
• another legal entity

So the sentence does not by itself tell you whether the owner/registered keeper is an individual or an organization. That would come from context.

You use van in the present tense when it is not a third-person equational sentence like this one.

For example:

• A tulajdonos itt van. = The owner is here.
• Az autó a garázsban van. = The car is in the garage.

But in simple identification:

• A tulajdonos az üzembentartó.
• not A tulajdonos az üzembentartó van.

So a good learner rule is:

• identity/classification in present, 3rd person → usually no van
• location/existence/other persons → often use van / vannak