Pociąg jedzie na wschód.

Polish does not have articles, so there is no separate word for the or a/an.

So pociąg can mean:

• a train
• the train

Which one is meant depends on context. In an isolated sentence like this, English might translate it as either The train is going east or A train is going east.

A rough pronunciation is po-chyongk, though that is only approximate.

A few helpful points:

• po sounds like po in pot, but without a strong English diphthong.
• ci before a vowel makes a soft ch-like sound, similar to ć.
• ą is a nasal vowel. Before g, it often sounds a bit like on or ong.
• Final g may sound slightly devoiced in normal speech, so learners sometimes hear something closer to k at the end.

You do not need to pronounce it exactly like English spelling suggests. The most important part is recognizing that ą is nasal and that cią is pronounced as one soft cluster.

This is a very common question.

In Polish:

• iść / idzie is used for going on foot
• jechać / jedzie is used for going by vehicle or for something traveling as a vehicle

So:

• On idzie do szkoły = He is walking to school
• On jedzie do szkoły = He is going to school by car, bus, bike, etc.
• Pociąg jedzie = The train is going / traveling

Since a train is a vehicle, jedzie is the natural verb here.

Here jedzie is the 3rd person singular form of jechać.

Because the subject is pociąg (train), it means something like:

• is going
• is traveling
• is heading
• sometimes is running (in the sense of transport service)

In this sentence, The train is going east or The train is heading east is a very natural translation.

Na wschód is a standard Polish expression meaning eastward or to the east in the sense of direction of movement.

With compass directions, Polish often uses:

• na północ = north / northward
• na południe = south / southward
• na wschód = east / eastward
• na zachód = west / westward

So jedzie na wschód means is going eastward.

This is not the same as saying it is located in the east. It describes the direction of movement.

It is in the accusative after na, because the sentence expresses movement in a direction.

So:

• na wschód = toward the east / eastward

For this noun, the accusative form looks the same as the nominative:

• nominative: wschód
• accusative: wschód

That is normal for many masculine inanimate nouns in Polish.

Not in this sentence.

Na wschód is the normal idiomatic way to express direction with compass points.

Do usually means movement to / into / toward a destination, but compass directions are not normally expressed that way in basic Polish. So a learner should treat na wschód as a set directional pattern.

Yes. Jedzie is present tense.

So the sentence means:

• The train is going east
• The train goes east (depending on context)

Like many Polish present-tense verbs, it can sometimes sound like English is going or simple present goes. Context tells you whether it is a current action, a habitual one, or part of a schedule.

Yes. Polish word order is more flexible than English word order.

The neutral order here is:

• Pociąg jedzie na wschód.

But other orders are possible for emphasis, for example:

• Na wschód jedzie pociąg.
• Jedzie pociąg na wschód.

These do not completely change the basic meaning, but they shift emphasis or sound more marked. For learners, the original order is the safest and most natural choice.

Not necessarily.

It means the train is moving in an eastward direction. It tells you the direction of travel, not necessarily the final destination.

So it could mean:

• the train is heading east right now
• the train’s route goes eastward
• the train is traveling toward some place that lies east of the current point

It does not by itself specify exactly where the train will end up.

In standard Polish, no. That would sound wrong for a train.

A train does not iść in the normal sense, because iść is for walking. A train jedzie.

So:

• Pociąg jedzie na wschód = correct
• Pociąg idzie na wschód = not standard in this meaning

No. They are related, but they do different jobs.

• na wschód = eastward / to the east
  This is an adverbial expression of direction.
• wschodni = eastern
  This is an adjective.

Examples:

• Pociąg jedzie na wschód. = The train is going east.
• wschodnia część kraju = the eastern part of the country

So in your sentence, you need na wschód, not wschodni.