Když přijede tramvaj, rychle nastoupíme a pojedeme jen dvě stanice.

Here když means when or once.

In this sentence, it introduces a time clause:

• Když přijede tramvaj... = When the tram arrives...

It is not really if here, because the sentence assumes the tram will arrive and describes what will happen then.

A useful rule:

• když = when / whenever
• jestli or pokud = if

Because přijede is perfective, and it refers to a completed future event: the tram will arrive.

• přijede = it will arrive
• přijíždí = it is arriving / it arrives / it usually arrives

In this sentence, the idea is not that the tram is in the process of coming, but that it reaches the stop and then something happens next. That is why přijede is the natural choice.

So the sequence is:

1. the tram arrives
2. we get on quickly
3. we ride only two stops

Formally, it looks like a present-tense form, but because the verb is perfective, it has future meaning.

That is a very common Czech pattern:

• perfective present form → future meaning

So:

• přijede = he/she/it will arrive
• not he/she/it arrives in the ordinary English sense

This is one of the first big aspect patterns learners have to get used to in Czech.

Because Czech often leaves out subject pronouns when the verb ending already shows who the subject is.

Both verb forms end in -me, which tells you the subject is we:

• nastoupíme = we will get on / we get on
• pojedeme = we will go / we will ride

So my is unnecessary here. You could say my nastoupíme, but it would usually add emphasis, something like we as opposed to someone else.

Nastoupíme means we will get on / we will board.

With transport, nastoupit is the normal verb for boarding:

• nastoupit do tramvaje = to get on a tram
• nastoupit do vlaku = to get on a train

So in this sentence:

• rychle nastoupíme = we’ll get on quickly

It does not mean simply enter in a general sense; it is specifically the natural verb for boarding a vehicle.

With verbs of motion like jet (to go by vehicle), Czech normally uses a simple future form:

• pojedu, pojedeš, pojedeme...

So:

• pojedeme = we will go / we will ride

That is the normal future here.

English speakers often expect a future with budu / budeme, but Czech frequently uses special future forms instead, especially with common motion verbs.

Also, jet specifically means going by vehicle, which fits a tram perfectly.

Because jet is the normal verb for moving by vehicle.

Compare:

• jít = to go on foot
• jet = to go by vehicle

Since you are on a tram, pojedeme is exactly the right verb.

So the sentence is literally close to:

• When the tram arrives, we’ll quickly board and we’ll go only two stops.

Natural English would usually say ride rather than go, but Czech uses jet here very naturally.

Tramvaj is in the nominative singular, because it is the subject of přijede.

• tramvaj přijede = the tram will arrive

The tram is the thing doing the action, so nominative is expected.

Because Czech can express distance or extent directly with a numeral phrase, much like English says only two stops.

So:

• pojedeme jen dvě stanice = we’ll ride only two stops

There is no need for a preposition like for.

The phrase dvě stanice is in the form used after the numeral dvě (two). For a learner, the key point is simply:

• two stops is expressed directly
• no extra word is needed

Because Když přijede tramvaj is a subordinate clause, and Czech separates it from the main clause with a comma.

So the structure is:

• Když přijede tramvaj, = subordinate time clause
• rychle nastoupíme a pojedeme jen dvě stanice. = main clause

This comma is standard Czech punctuation.

Yes, Czech word order is fairly flexible, although some versions sound more natural than others.

The original sentence is very natural:

• Když přijede tramvaj, rychle nastoupíme a pojedeme jen dvě stanice.

You could also move things for emphasis, for example:

• Když přijede tramvaj, nastoupíme rychle...
• ...pojedeme dvě stanice jen... → grammatically possible in some contexts, but much less natural here

A few practical points:

• rychle usually stays near the verb it modifies
• jen usually goes near the word or phrase it limits
• jen dvě stanice clearly means only two stops

So yes, the word order can move, but the original version is a very good, neutral model.

In this sentence, it most naturally refers to one specific future situation:

• When the tram arrives, we’ll get on quickly...

But když can also be used for repeated or habitual situations, depending on context:

• Když přijede tramvaj, lidé nastupují. = When/whenever the tram arrives, people get on.

So když itself does not force only one meaning. The rest of the sentence and the context tell you whether it is:

• a one-time future event, or
• a repeated situation

Here, because of nastoupíme and pojedeme, it clearly sounds like a single future plan.