Az úszó gyors az úszósávban.

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

So:

• Az úszó gyors. = The swimmer is fast.
• not usually Az úszó van gyors.

This is completely normal Hungarian.

You do use van in other situations, for example:

• Én gyors vagyok. = I am fast.
• Te gyors vagy. = You are fast.
• Az úszó gyors volt. = The swimmer was fast.

So in your sentence, the missing is is not a mistake; it is standard Hungarian grammar.

Hungarian has two forms of the definite article:

• a
• az

Which one you use depends on the sound that follows:

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

Here:

• úszó starts with ú, a vowel
• úszósávban also starts with ú, a vowel

So you get:

• az úszó
• az úszósávban

This is similar to English a/an, but Hungarian does this with the definite article instead of the indefinite one.

Because Hungarian uses the article separately with each definite noun phrase.

In this sentence:

• Az úszó = the swimmer
• az úszósávban = in the swimming lane

Both are definite, so both can have the article.

English does the same kind of thing:

• The swimmer is fast in the lane.

Hungarian is not saying the same az twice for no reason; each one belongs to a different noun phrase.

Here, úszó means swimmer.

It comes from the verb úszik = to swim. The form úszó can function like a participle, something like swimming or one who swims, and in many contexts it becomes a noun:

• úszó = swimmer

So in this sentence, az úszó is understood as the swimmer, not just the swimming one.

Hungarian often does this: a verb-based form can work as a noun if the context makes it clear.

Gyors is an adjective, meaning fast.

In this sentence, it describes the swimmer, so Hungarian uses the adjective:

• Az úszó gyors. = The swimmer is fast.

If you wanted to say that the swimmer swims quickly, then you would use the adverb gyorsan:

• Az úszó gyorsan úszik. = The swimmer swims quickly.

So the difference is:

• gyors = describes a person or thing: fast
• gyorsan = describes an action: quickly / fast

The ending -ban / -ben is a case ending meaning in.

So:

• úszósáv = swimming lane
• úszósávban = in the swimming lane

Hungarian often uses case endings where English uses prepositions.

A few similar examples:

• házban = in the house
• iskolában = in the school
• vízben = in the water

In your sentence, az úszósávban means in the swimming lane.

This is because of vowel harmony, which is very important in Hungarian.

Hungarian suffixes often come in two versions:

• -ban
• -ben

Words with mostly back vowels usually take -ban. Words with mostly front vowels usually take -ben.

In úszósáv, the vowels are ú, ó, á, which are back vowels, so the correct form is:

• úszósávban

Compare:

• házban = in the house
• kertben = in the garden

So the ending is chosen to match the word’s vowel pattern.

It has three parts:

• úszó = swimming / swimmer-related
• sáv = lane
• -ban = in

So:

• úszósáv = swimming lane
• úszósávban = in the swimming lane

Hungarian makes a lot of compound nouns, just like English does:

• swimming pool
• bathroom door
• school bus

So úszósáv is a very normal Hungarian-style compound word.

Hungarian word order is more flexible than English word order, but different orders can change the emphasis.

Your sentence:

• Az úszó gyors az úszósávban.

This is a natural way to say something like The swimmer is fast in the swimming lane.

But you could also say:

• Az úszósávban gyors az úszó.

That would put more emphasis on in the swimming lane—as if contrasting it with somewhere else.

So the basic meaning can stay similar, but the word order helps show what is new, important, or contrasted information.

A few key pronunciation points:

• ú and ó are long vowels
• á is also a long vowel, pronounced differently from short a
• sz is pronounced like English s
• s by itself is pronounced like English sh

So:

• úszó sounds roughly like oo-soh
• úszósávban sounds roughly like oo-soh-shaav-bon

More carefully:

• ú = long oo
• sz = s
• sáv begins with s, so that part sounds like shaav

This is a very common beginner issue, because English speakers often expect sz to sound like z or s to sound like s, but Hungarian spelling works differently.