A tömés formája jó.

In Hungarian, the verb van (to be) is usually left out in the present tense, third person when you are simply saying that something is something.

So:

• A tömés formája jó. = The filling’s shape is good.

But in other tenses, or in first/second person, the verb appears:

• A tömés formája jó volt. = The filling’s shape was good.
• A tömés formája jó lesz. = The filling’s shape will be good.
• Jó vagyok. = I am good.

So the missing is is completely normal here.

Because formája means its shape or the shape of it.

Hungarian usually shows possession by putting a possessive suffix on the possessed thing:

• forma = shape
• formája = its shape / his shape / her shape

In a tömés formája, the possessor is tömés (filling), and the possessed noun is formája (its shape), so the whole phrase means:

• a tömés formája = the filling’s shape / the shape of the filling

This is a very common Hungarian structure.

The -ja is a third-person singular possessive ending. It shows that something belongs to him/her/it.

Here:

• forma = shape
• formá-ja = its shape

Because tömés is the thing that has the shape, Hungarian marks that relationship on forma.

You will often see similar patterns:

• a ház teteje = the house’s roof
• a könyv címe = the book’s title
• az autó kereke = the car’s wheel

So -ja / -je often corresponds to English ’s or of the.

Because Hungarian commonly uses the definite article in this kind of possessive phrase.

• a tömés formája = the filling’s shape

This is normal Hungarian structure: the possessor often has the definite article.

Compare:

• a könyv borítója = the book’s cover
• a fiú kabátja = the boy’s coat

Without the article, the phrase would usually sound incomplete, unnatural, or very context-dependent.

Hungarian has two forms of the definite article:

• a before a consonant
• az before a vowel

Since tömés starts with t, which is a consonant, you use a:

• a tömés

Compare:

• az alma = the apple
• az ember = the person
• a könyv = the book

Because Hungarian adjectives do not work like adjectives in many Indo-European languages. They do not agree for gender, and Hungarian has no grammatical gender at all.

So jó stays jó here:

• A tömés formája jó. = The filling’s shape is good.
• A tömések formája jó. = The fillings’ shape is good.
• A forma jó. = The shape is good.

The adjective stays the same.

The sentence has a very natural, neutral order:

• A tömés formája = topic / what we are talking about
• jó = comment / what is being said about it

So the structure is roughly:

• [The filling’s shape] [good].

Hungarian word order is flexible, but changes emphasis. For example:

• A tömés formája jó. = neutral; the filling’s shape is good.
• Jó a tömés formája. = emphasis on good; it’s the shape of the filling that is good.

Both are possible, but they do not feel exactly the same.

Yes. Hungarian also has a dative possessor structure:

• A tömésnek a formája jó.

This also means The filling’s shape is good, but it can sound more explicit or more marked depending on context.

The shorter version without -nek is very common and natural:

• A tömés formája jó.

So for a learner, the version in your sentence is the basic one to remember first.

A rough pronunciation guide is:

• A tömés formája jó.
• roughly: aw TÖ-maysh FOR-maa-yaw yoh

A few useful pronunciation points:

• ö is a rounded vowel, somewhat like German ö
• é is a long ay-like sound
• s in Hungarian is pronounced like English sh
• j is pronounced like English y
• ó and á are long vowels
• stress is usually on the first syllable of each word:
  • TÖmés
  • FORmája

So:

• tömés sounds roughly like TÖ-maysh
• formája sounds roughly like FOR-maa-yaw
• jó sounds like yoh

Yes, very often.

Hungarian does not normally use a separate word like English of here. Instead, it uses a possessive construction:

• a tömés formája = the filling’s shape
• literally something like the filling its-shape

So when English uses:

• the shape of the filling
• the filling’s shape

Hungarian often uses:

• a tömés formája

That is one of the most important sentence patterns to get comfortable with in Hungarian.