Jutro idziemy na mecz na nowym stadionie.

In Polish, the present tense of an imperfective verb is very often used for a planned future.

So idziemy literally looks like we are going / we go, but in a sentence with jutro (tomorrow), it naturally means:

We’re going tomorrow / We’re going to go tomorrow.

This is very similar to English We’re going tomorrow, where the form looks present but the meaning is future because of the time word.

Yes. That is also correct, but the nuance is a little different.

• idziemy suggests a plan or arrangement already in place
• pójdziemy is a perfective future, often sounding more like we will go

So:

• Jutro idziemy na mecz... = Tomorrow we’re going to the match...
• Jutro pójdziemy na mecz... = Tomorrow we’ll go to the match...

Both can work, but idziemy is especially common for fixed plans.

Because it introduces two different ideas:

1. na mecz = to a match
2. na nowym stadionie = at the new stadium

So the two na phrases do different jobs:

• the first one shows the destination/event
• the second one shows the location

This is normal in Polish. Even though the same preposition is used, the meaning depends on the context and the case that follows.

Because after na, Polish uses different cases depending on the meaning.

Here, na mecz expresses movement toward an event, so Polish uses the accusative case.

• nominative: mecz
• accusative: mecz

For this noun, nominative and accusative happen to look the same.

Compare:

• Idziemy na mecz. = We are going to a match.
• Jesteśmy na meczu. = We are at a match.

In the second sentence, there is no movement; it is a location/situation, so Polish uses the locative: meczu.

Because this phrase describes where the match is taking place, not where you are moving.

• na nowy stadion would mean onto/to the new stadium as a destination
• na nowym stadionie means at/on the new stadium as a location

After na:

• accusative often marks movement toward
• locative often marks location

So in this sentence:

• idziemy na mecz = movement to the event
• na nowym stadionie = the event is located there

They are both in the locative case, because they follow na in a location meaning.

Base forms:

• nowy = new
• stadion = stadium

Locative singular:

• nowym
• stadionie

The adjective must agree with the noun in gender, number, and case, so both change together:

• nowy stadion = nominative
• na nowym stadionie = locative after na

In natural English, it usually means at the new stadium.

Polish often uses na with places where English might use at, in, or on, depending on the noun and idiom.

So although na often gets taught as on, you should not translate it mechanically every time.

Here the best natural meaning is:

at the new stadium

In Polish, subject pronouns are often omitted because the verb ending already shows the subject.

• idziemy = we go / we are going

So my is not necessary.

You can add my if you want emphasis, for example:

My jutro idziemy na mecz
= We are the ones going tomorrow

But in a neutral sentence, leaving it out is more natural.

Yes. Polish word order is more flexible than English, though not completely free. The basic meaning stays the same, but the emphasis changes.

For example:

• Jutro idziemy na mecz na nowym stadionie.
  Neutral; tomorrow is highlighted first.

• Idziemy jutro na mecz na nowym stadionie.
  Also natural; a bit more conversational.

• Na nowym stadionie jutro idziemy na mecz.
  Possible, but now the location is strongly foregrounded.

So the original sentence is a very natural, neutral choice.

This is a very common learner question.

• iść / idziemy literally relates to going on foot
• jechać / jedziemy relates to going by vehicle

But in some contexts, especially with events, idziemy na mecz can sound natural even if you are not literally walking the whole way. It can simply mean we’re going to the match.

Still, if you want to be physically precise:

• Idziemy na mecz. = We’re going to the match. / We’re walking to the match.
• Jedziemy na mecz. = We’re going to the match by car/bus/train.

A rough guide:

• Jutro ≈ YOO-tro
• idziemy ≈ ee-JDZYE-my
• mecz ≈ metch
• nowym ≈ NO-vim
• stadionie ≈ sta-dyo-NYE

A few useful pronunciation notes:

• j in Polish sounds like English y in yes
• cz sounds like English ch in match, but harder
• dzi in idziemy is a soft sound, something like j
  • dy
• nie at the end of stadionie sounds like nye

If you want, I can also break the whole sentence down syllable by syllable.