A hosszú távhoz kitartás kell.

It can be both, but here it is idiomatic.

• Literally, hosszú táv means long distance or long range
• In everyday usage, it often means the long term or the long run

So in this sentence, it is not about physical distance. It is about something that takes time and sustained effort.

Because Hungarian adds the suffix -hoz / -hez / -höz to show a meaning like to, toward, or in many cases for.

In this pattern:

• X-hoz Y kell = Y is needed for X

So:

• a hosszú távhoz = for the long term
• kitartás kell = perseverance is needed

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

The three forms are chosen based on the vowels in the word:

• -hoz after back vowels
• -hez after front unrounded vowels
• -höz after front rounded vowels

The word táv contains á, which is a back vowel, so the correct form is távhoz.

A is the definite article, meaning the.

Here it belongs to the whole phrase hosszú távhoz, so:

• a hosszú távhoz = for the long term

Hungarian often uses the definite article in places where English may or may not use the, so this can feel a little different from English usage.

Because kitartás is an abstract noun used in a general sense, like perseverance in English.

Hungarian often leaves abstract nouns bare when talking about them generally:

• kitartás = perseverance, persistence
• türelem = patience
• idő = time

If you said a kitartás, it would sound more like the perseverance, meaning some specific perseverance already known from the context.

Kell has a few related uses. Its basic idea is to be needed or must / have to.

In this sentence, it means:

• is needed

So:

• kitartás kell = perseverance is needed

This is not the must meaning here. It is the need meaning.

A helpful breakdown is:

• a hosszú távhoz = for the long term
• kitartás = perseverance
• kell = is needed

So the sentence is structured like:

• For the long term, perseverance is needed

Grammatically, kitartás is the thing that is needed, so it functions like the subject.
A hosszú távhoz is a complement showing what it is needed for.

Yes. Hungarian word order is flexible, and it often shows topic and emphasis rather than following one fixed English-style order.

In this sentence:

• A hosszú távhoz comes first as the topic: as for the long term
• kitartás comes right before kell, which gives it emphasis

So the sentence feels a bit like:

• For the long run, what you need is perseverance

Other possible word orders are also natural, for example:

• Kitartás kell a hosszú távhoz.
• A hosszú távhoz kell kitartás.

These are very similar in meaning, but the emphasis shifts slightly.

Because here it is a normal adjective + noun combination:

• hosszú = long
• táv = term, range, distance

So it is written as two words, just like long term in English.

Hungarian does form many one-word compounds, but in this sentence hosszú táv is simply a phrase, not a single compound word.