A rajt központi helyen van.

A is the Hungarian definite article, the equivalent of the.

Hungarian has two forms:

• a before a consonant
• az before a vowel

Since rajt starts with r, Hungarian uses a: a rajt = the start.

Rajt usually means start, especially the start of a race, event, or competition. Depending on context, it can refer to:

• the act of starting
• the starting point
• the start line

In this sentence, it most naturally refers to the start location or starting point.

Központi means central.

It comes from központ, which means center or centre, plus the adjectival ending -i. So:

• központ = center
• központi = central

This -i ending is a common way in Hungarian to make adjectives from nouns.

Because Hungarian uses case endings to show location.

• hely = place
• helyen = in/at a place

So központi helyen means something like in a central place or at a central location.

English uses a separate preposition such as in or at, but Hungarian often adds an ending to the noun instead.

Here -en is the superessive ending, part of the -on / -en / -ön set.

This case often corresponds to English on, but with some nouns it is also used where English would say in or at. With hely (place), helyen is the normal way to say in/at a place.

So even though the case is traditionally called superessive, the best translation here is simply in a central location or at a central place.

In Hungarian adjective + noun phrases, the case ending normally goes on the noun, not on the adjective.

So:

• központi hely = central place
• központi helyen = in/at a central place

The adjective központi stays unchanged, and the noun hely carries the case ending.

That is a very common question.

Hungarian often omits van in the present tense, third person, when the predicate is a noun or an adjective:

• A rajt fontos. = The start is important.
• Ő tanár. = He/She is a teacher.

But when the predicate is a location or another adverbial expression, van is usually required:

• A rajt itt van. = The start is here.
• A rajt központi helyen van. = The start is in a central location.

So in this sentence, van stays because the sentence is telling us where the start is.

No, Hungarian word order is flexible, but different orders give different emphasis.

A rajt központi helyen van is a normal, neutral sentence:
As for the start, it is in a central location.

You could also say:

• Központi helyen van a rajt.

This puts more emphasis on the location.

So the sentence order is not random: it helps show what the speaker is treating as the topic and what part is being highlighted.

Yes, but it is not exactly the same.

• központi helyen = in a central location, in a well-placed spot
• a központban = in the center / in the town center / downtown / in the central area

So A rajt a központban van would mean the start is literally in the center.
A rajt központi helyen van is a bit broader and means the start is centrally located.

Because helyben usually means something like:

• locally
• on the spot
• without moving elsewhere

It is a different expression.

For the idea in/at a place, Hungarian normally uses helyen, not helyben. So:

• jó helyen van = it is in a good place
• központi helyen van = it is in a central place

That is the natural pattern in Hungarian.