A járat onnan indul.

Járat is a fairly broad noun. In this kind of sentence, it usually means a service, route, flight, bus, train service, or some other scheduled departure, depending on context.

So A járat onnan indul. could refer to:

• a bus service
• a train service
• a flight
• another regular transport connection

Hungarian often uses járat where English would choose a more specific word from context.

A is the Hungarian definite article, meaning the.

So:

• a járat = the service / the flight / the bus
• egy járat = a service / a flight / a bus

Hungarian uses a before consonant sounds and az before vowel sounds:

• a járat
• az autó

Onnan means from there.

It is the “from” form connected to location. Compare:

• ott = there
• oda = to there / there(to)
• onnan = from there

So this pattern is very useful:

• Itt = here
• ide = to here
• innen = from here

and

• ott = there
• oda = to there
• onnan = from there

Because indul means sets off / departs / starts, and with that idea you usually need the starting point, so Hungarian uses from there, not just there.

• ott = at that place / there
• onnan = from that place / from there

So if the meaning is that the service begins its journey at that location, onnan is the right choice.

Indul is the 3rd person singular present tense form of the verb indul.

It can mean:

• starts
• sets off
• departs
• leaves

In this sentence, the subject is a járat, which is singular, so indul matches it:

• A járat indul. = The service departs.

This verb is often used for departures of vehicles, routes, services, and also people:

• A busz indul. = The bus is leaving.
• Holnap indulok. = I’m leaving tomorrow.

Because indul is an intransitive verb here: it does not take a direct object.

Hungarian has definite and indefinite conjugation mainly when a verb takes a direct object:

• Olvasok egy könyvet. = I am reading a book.
• Olvasom a könyvet. = I am reading the book.

But indul does not work like that in this sentence. The service is not acting on an object; it is simply departing. So there is no definite/indefinite contrast to worry about here.

Yes, the word order can change, and the change usually affects emphasis rather than basic meaning.

• A járat onnan indul.
  Neutral statement: The service departs from there.

• Onnan indul a járat.
  Puts more emphasis on from there. This can sound like It’s from there that the service departs or The service departs from there with stress on the location.

Hungarian word order is quite flexible, but it is not random. The element before the verb often gets special focus or emphasis.

A simple learner-friendly approximation:

• járat ≈ yaa-rat
• onnan ≈ on-nan
• indul ≈ in-dool

A few useful points:

• j in Hungarian sounds like English y in yes
• á is a long vowel, roughly like aah
• u in indul is pronounced like oo

So járat starts more like yaa-, not like English j in jam.

Most commonly in a sentence like this, yes, it refers to some kind of transport service or scheduled route. But járat can appear in other contexts too, because it comes from the idea of something that runs regularly.

For example, depending on context, it can refer to:

• a bus route
• a train service
• a flight
• a postal delivery round
• a scheduled run or service

So learners should rely on context to choose the best English equivalent.

Yes, indul is also used for people. It means to set off, to leave, or to start out.

Examples:

• Most indulok. = I’m leaving now.
• Mikor indultok? = When are you leaving?
• A vonat hatkor indul. = The train leaves at six.

So it works both for people and for transport.

Yes, it is completely natural. It is a normal, simple sentence you might hear in travel, timetable, or direction-giving contexts.

For example, someone might say it when explaining:

• where a bus departs from
• where a train service starts
• where a flight or route begins

It is short, clear, and idiomatic.