Az önrész nagy, holott a kárösszeg kicsi.

Because Hungarian often leaves out the verb to be in the present tense, 3rd person when the predicate is a noun or an adjective.

So:

• Az önrész nagy. = The deductible is large.
• A kárösszeg kicsi. = The amount of damage is small.

This is called the zero copula.

But Hungarian does use van / vannak in other situations, for example:

• in the past: Az önrész nagy volt. = The deductible was large.
• in the future: Az önrész nagy lesz. = The deductible will be large.
• with location/existence: A pénz a számlán van. = The money is in the account.

So the missing is here is completely normal.

Hungarian has two forms of the definite article:

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

So:

• az önrész because önrész starts with ö, a vowel
• a kárösszeg because kárösszeg starts with k, a consonant

This is similar to English a / an, but Hungarian does it with the definite article.

Önrész is a common insurance term. It means the part of the cost that you yourself must pay before the insurer pays the rest.

A useful way to remember it is that it is built from:

• ön = self
• rész = part

So literally it is something like one’s own part.

In insurance English, the best translation is usually deductible. In some contexts it can also be understood as copay or excess, depending on the insurance system.

Holott means although, even though, or sometimes whereas.

It introduces a contrast between two facts:

• Az önrész nagy, holott a kárösszeg kicsi.
• The deductible is large, although the amount of damage is small.

Compared with similar words:

• de = but
  This is the most basic contrast word.
• bár / noha = although / though
  These are also common concessive words.
• holott often sounds a bit more formal or written, and can suggest a surprising or illogical contrast.

So here holott fits well because the sentence suggests: the deductible is large despite the fact that the damage amount is small.

Because here the adjectives are predicates, not noun modifiers.

Compare these two patterns:

• A nagy önrész = the large deductible
  Here nagy directly describes the noun inside the noun phrase.
• Az önrész nagy = the deductible is large
  Here nagy is the predicate.

So in your sentence:

• Az önrész nagy = The deductible is large.
• A kárösszeg kicsi = The amount of damage is small.

This is a very important difference in Hungarian word order.

Both kis and kicsi relate to small, but they are not used in exactly the same way.

A very useful rule is:

• kis is very common before a noun
• kicsi is the normal form when the adjective stands by itself as the predicate

So:

• kis összeg = a small amount
• Az összeg kicsi. = The amount is small.

That is why kicsi is natural in a kárösszeg kicsi.

You may also hear kicsi before a noun sometimes, but in basic learner usage, the contrast above is a good rule to follow.

Because Hungarian often writes compound nouns as one word.

Here:

• kár = damage, loss
• összeg = amount, sum

So kárösszeg literally means damage amount or claim amount.

This is very normal in Hungarian. English often uses separate words where Hungarian prefers compounds.

Yes. In Hungarian, when two clauses are linked by conjunctions such as holott, a comma is normally used.

So:

• Az önrész nagy, holott a kárösszeg kicsi.

The comma marks the boundary between the two clauses:

1. Az önrész nagy
2. holott a kárösszeg kicsi

This is standard Hungarian punctuation.

Yes, Hungarian word order is flexible, but changing it changes the focus or emphasis.

The original sentence is neutral and clear:

• Az önrész nagy, holott a kárösszeg kicsi.

You could also say:

• Holott a kárösszeg kicsi, az önrész nagy.

This puts more attention on the surprising background fact first: the damage amount is small.

So the original version is a natural statement, while a different order can sound more emphatic or stylistically marked.

Yes, it sounds somewhat formal or at least connected to insurance/business language, mainly because of words like:

• önrész
• kárösszeg
• holott

In everyday casual speech, a speaker might choose simpler wording, especially replacing holott with de or pedig, depending on the exact meaning.

So the sentence is perfectly correct, but it has a slightly formal, written, or professional feel.