A fogorvos betömi az őrlőfogat.

Both a and az mean the.

Hungarian uses:

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

So here:

• a fogorvos = the dentist
• az őrlőfogat = the molar

This is a bit like English a/an, except in Hungarian these are definite articles, so they both mean the, not a/an.

fogorvos is a compound word:

• fog = tooth
• orvos = doctor

So it literally means tooth doctor, which is the normal Hungarian word for dentist.

Hungarian uses compound words very often, so this is a useful pattern to get used to.

betömi is the verb form here, and it is the 3rd person singular present definite form of betöm.

Why -i?

Because Hungarian verbs can have two main conjugation patterns:

• indefinite conjugation
• definite conjugation

If the verb has a definite direct object, Hungarian usually uses the definite form of the verb.

Here the object is az őrlőfogat = the molar, which is definite, so the sentence uses:

• betömi = fills it / fills the ...

Compare:

• betöm egy fogat = fills a tooth
• betömi a fogat = fills the tooth

So the -i is not random; it is showing agreement with a definite object.

The basic verb töm means something like:

• to stuff
• to pack
• to fill
• to plug

The prefix be- often adds the sense of in or into.

So betöm means something like:

• to fill in
• to plug up

In a dental context, this is the natural verb for filling a tooth.

So betömi is not just a random verb form; it is built from:

• be-
  • töm
    • definite ending

Because őrlőfogat is the direct object of the sentence, and Hungarian marks direct objects with the accusative ending, usually -t.

So:

• őrlőfog = molar
• őrlőfogat = molar + accusative ending

In this word, a linking vowel appears before the -t, so you get:

• őrlőfog → őrlőfogat

This is a very common Hungarian pattern. The exact linking vowel can vary from word to word, so it is something learners gradually get used to.

őrlőfog is also a compound word:

• őrlő = grinding
• fog = tooth

So literally it means grinding tooth, which corresponds to molar.

The first part, őrlő, comes from the verb őröl, meaning to grind.

This is another nice example of how transparent many Hungarian compounds can be once you know the parts.

No, Hungarian word order is fairly flexible.

This sentence has a neutral, straightforward order:

• A fogorvos betömi az őrlőfogat.

Very roughly, this is:

• topic: A fogorvos
• action: betömi
• object: az őrlőfogat

But Hungarian can change word order to change emphasis or focus.

For example, if you strongly emphasize the object, you could move things around. Also, when something is focused or negated, the verbal prefix often separates from the verb.

For example:

• A fogorvos nem tömi be az őrlőfogat. = The dentist is not filling the molar.

So the version you were given is the neutral, unmarked one.

For many English speakers, these are tricky vowels.

• ö is a short front rounded vowel
• ő is the same sound, but long

A rough approximation:

• similar to German ö
• or French eu in some words

So:

• betömi has short ö
• őrlőfogat has long ő

Also, Hungarian stress is usually on the first syllable of the word:

• FO-gor-vos
• BE-tö-mi
• ŐR-lő-fo-gat

That first-syllable stress is very consistent in Hungarian.

Not perfectly, because Hungarian and English package information differently.

A very literal breakdown is:

• A fogorvos = the dentist
• betömi = fills it / fills the definite object
• az őrlőfogat = the molar

But natural English would normally just say:

• The dentist fills the molar
• or, depending on context, The dentist is filling the molar
• or more idiomatically in a dental context, The dentist fills the molar tooth

So when learning Hungarian, it is useful to notice both:

• the literal pieces
• the natural English equivalent

They are not always identical word-for-word.