Amint kezdődik a jótékonysági futás, a csapattársak együtt futnak.

Amint usually means as soon as or the moment that. It often suggests that one action follows another immediately.

So in this sentence, amint kezdődik... gives the idea of:

• as soon as the charity run begins
• the moment the charity run starts

Amikor usually means when, and it is often more neutral and less immediate.

Compare:

• Amint kezdődik a futás... = As soon as the run begins...
• Amikor kezdődik a futás... = When the run begins...

In many contexts they can overlap, but amint emphasizes quick sequence more strongly.

Because kezdődik is the intransitive verb meaning to begin or to start, while kezd is usually transitive and means to begin/start something.

• A futás kezdődik. = The run begins.
• A szervezők kezdik a futást. = The organizers start the run.

In your sentence, a jótékonysági futás is the thing that begins by itself, so kezdődik is the natural choice.

Also, the -dik ending here is part of the verb itself. It does not mean passive in the same way English does.

Hungarian often uses the present tense for future events, especially when the future is:

• scheduled,
• expected,
• or clear from context.

That is very common after time words and conjunctions like amint, amikor, miután, and so on.

So:

• Amint kezdődik a jótékonysági futás, ... literally uses present tense, but it can still mean
• As soon as the charity run begins, ...

English often prefers a future idea in meaning, but Hungarian does not need a special future form here.

Jótékonysági comes from jótékonyság, which means charity or charitable activity.

The ending -i often turns a noun into an adjective meaning something like:

• related to
• connected with
• of

So:

• jótékonyság = charity
• jótékonysági = charitable / charity-related

That is why:

• jótékonysági futás = charity run

This -i adjective pattern is very common in Hungarian.

Examples:

• iskola → iskolai = school / school-related
• ország → országi in some contexts, though more limited
• város → városi = city / urban

Futás is a noun.

It comes from the verb fut = to run.

The ending -ás / -és often creates a noun from a verb, similar to English -ing or nouns like running, movement, arrival, depending on context.

So:

• fut = to run
• futás = running / a run / a race-event, depending on context

In a jótékonysági futás, it refers to the event: the charity run.

Because Hungarian uses the definite article a / az much more regularly than English.

Here:

• a jótékonysági futás = the charity run
• a csapattársak = the teammates

The article shows that these are specific, identifiable things or people.

English sometimes drops the where Hungarian keeps it, but in this sentence both are specific:

• a particular charity run
• a particular group of teammates

So the definite article is fully natural here.

Csapattársak breaks down like this:

• csapat = team
• társ = companion / partner / fellow member
• csapattárs = teammate
• csapattársak = teammates

The plural ending here is -ak, which is one form of the Hungarian plural marker -k.

So:

• csapattárs = one teammate
• csapattársak = more than one teammate

Hungarian plural endings change shape depending on the word, but the core plural marker is -k.

Futnak is the correct 3rd person plural form of fut = to run.

Here the verb has no direct object. The teammates are simply running.

So:

• a csapattársak futnak = the teammates are running

Hungarian has different conjugation patterns depending on whether there is a definite direct object, but fut here is intransitive, so futnak is the natural form.

Very simply:

• futok = I run
• futsz = you run
• fut
• futunk
• futtok
• futnak

Együtt means together.

In Hungarian, word order is strongly influenced by emphasis and information structure, not just fixed grammar rules. Putting együtt before the verb is very natural and often gives it a close connection to the verb:

• a csapattársak együtt futnak = the teammates run together

This is a neutral, natural way to say it.

You may also hear:

• A csapattársak futnak együtt.

That is also possible, but the rhythm and emphasis are slightly different. The version with együtt before the verb is very common when together is part of the main action being described.

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

• Amint kezdődik a jótékonysági futás... is a very natural neutral phrasing in this kind of clause.
• Amint a jótékonysági futás kezdődik... is also grammatical, but it puts more topic-like attention on a jótékonysági futás.

Hungarian word order is flexible. It often reflects what is already known, what is being emphasized, and what the speaker wants to foreground.

So this sentence uses a natural flow where the verb comes first in the subordinate clause after amint.

Yes. Elkezdődik is also very natural.

Compare:

• kezdődik = begins
• elkezdődik = begins / gets started

The prefix el- can add a sense of the action getting underway. In many everyday contexts, both versions work.

So these are both acceptable:

• Amint kezdődik a jótékonysági futás...
• Amint elkezdődik a jótékonysági futás...

The second one may sound a little more explicitly like gets started, but the difference is small in many situations.

Because the sentence has two clauses:

1. Amint kezdődik a jótékonysági futás
2. a csapattársak együtt futnak

In Hungarian, when a subordinate clause comes before the main clause, it is normally separated by a comma.

So the comma here works much like in English:

• As soon as the charity run begins, the teammates run together.

It marks the boundary between the time clause and the main statement.