A röntgenfelvétel mutatja az őrlőfog formáját.

Hungarian has two forms of the definite article:

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

So:

• a röntgenfelvétel because röntgenfelvétel starts with r
• az őrlőfog because őrlőfog starts with the vowel ő

This is similar to English a / an, but Hungarian uses this distinction only for the definite article.

Röntgenfelvétel is a compound noun:

• röntgen = X-ray
• felvétel = recording, image, shot, taken image

So röntgenfelvétel means an X-ray image or X-ray recording, not the radiation itself. In this sentence, it means the image that shows something.

Because Hungarian uses a definite conjugation when the verb has a definite object.

Here the object is az őrlőfog formáját, which is definite, so the verb must be in the definite form:

• mutat = shows, is showing something nonspecific
• mutatja = shows it / shows the specific thing

So mutatja is used because the sentence is talking about a specific, definite thing: the shape of the molar.

It is also a compound:

• őrlő = grinding
• fog = tooth

So literally it means grinding tooth, which is the Hungarian word for molar.

This is a very common feature of Hungarian vocabulary: many words are built as transparent compounds.

Formáját has several parts:

• forma = shape, form
• formája = its shape / his shape / her shape / the shape of it
• formáját = its shape as a direct object

Breakdown:

• forma
• • -ja = 3rd person singular possessive suffix
• • -t = accusative ending

Also notice that final a often becomes long á before suffixes:

• forma
• formája
• formáját

So formáját means its shape or, in this context, the shape of the molar, in the object form.

Because Hungarian usually marks possession on the possessed noun, not with a separate word like English its.

In English, you say:

• the molar's shape
• the shape of the molar

In Hungarian, this is expressed with the possessed noun carrying a possessive ending:

• őrlőfog formája = the molar's shape

So the idea of its / of the molar is built into the structure, especially into formája.

In Hungarian, a possessed noun phrase usually takes one article for the whole phrase, placed at the beginning:

• az őrlőfog formáját = the molar's shape / the shape of the molar

Hungarian does not normally repeat the article before both nouns in this kind of structure.

So the article az belongs to the whole noun phrase, not just to őrlőfog.

Because őrlőfog is not the direct object here. The direct object is the whole phrase az őrlőfog formáját, and the head of that phrase is formáját.

That is why the accusative ending appears on formáját, not on őrlőfog.

As for -nak/-nek: Hungarian has two common possessive patterns.

1. Unmarked possessor

   • az őrlőfog formája

2. Marked possessor

   • az őrlőfognak a formája

Both can mean the shape of the molar. The sentence uses the first, simpler pattern.

The sentence has a normal, neutral order:

• A röntgenfelvétel = topic/subject
• mutatja = verb
• az őrlőfog formáját = object

So it is a straightforward The X-ray shows the shape of the molar.

Hungarian word order is flexible, though. If you move the object before the verb, you usually add emphasis or focus:

• Az őrlőfog formáját mutatja a röntgenfelvétel.

This gives stronger emphasis to the shape of the molar.

Grammatically, őrlőfog is singular, so it means molar, not molars.

In most contexts, this sentence refers to one specific molar, especially because the whole object phrase is definite. In technical or descriptive language, singular forms can sometimes sound more general, but the basic grammatical meaning here is singular: the molar.