Když máš dobrou mapu, víš, kde je pošta i pekárna.

Here když most naturally means when, but in general Czech když can sometimes overlap with if/whenever in broad, general statements.

So:

• Když máš dobrou mapu... = When you have a good map...
• In natural English, this can also feel like If you have a good map...

The exact nuance depends on context, but for a learner, when is the safest basic meaning.

Czech often leaves out subject pronouns when they are clear from the verb ending.

Here:

• máš = you have
• víš = you know

Because the -š ending already shows you (singular, informal), Czech does not need to say ty.

You could say Když ty máš..., but that would usually add emphasis, something like When you* have...

Máš is the 2nd person singular present form of mít (to have).

So:

• mám = I have
• máš = you have
• má = he/she/it has

This sentence uses the informal singular you. If you were speaking to more than one person, or using formal you, you would say máte.

Because mapa is the direct object of máš, so it must be in the accusative case, not the nominative.

Dictionary form:

• dobrá mapa = a good map (nominative)

In this sentence:

• máš dobrou mapu = you have a good map (accusative)

Both words change because the adjective must agree with the noun:

• dobrá → dobrou
• mapa → mapu

This is a very common pattern for feminine nouns ending in -a.

Because Czech distinguishes between two kinds of to know:

• vědět = to know a fact, piece of information, answer, etc.
• znát = to know a person, place, or thing by familiarity

Here the sentence means you know where..., so it is about information. That is why Czech uses vědět, and the form here is víš.

Compare:

• Vím, kde je pošta. = I know where the post office is.
• Znám tu poštu. = I know that post office / I’m familiar with it.

Víš is the 2nd person singular present form of vědět (to know).

A few useful forms:

• vím = I know
• víš = you know
• ví = he/she/it knows

Again, this is the informal singular you. The formal/plural form would be víte.

Because Czech uses commas to separate subordinate clauses from the main clause.

The sentence has three parts:

• Když máš dobrou mapu = subordinate clause introduced by když
• víš = main clause
• kde je pošta i pekárna = subordinate clause after víš

So the commas mark those boundaries:

• Když máš dobrou mapu, víš, kde je pošta i pekárna.

This is standard Czech punctuation.

Kde means where.

After verbs like vědět (to know), Czech often uses a clause beginning with kde, kdy, proč, jak, etc.

So:

• víš, kde je pošta = you know where the post office is

This is like an embedded question. It is not asking someone directly; it is reporting what someone knows.

I usually means also, too, or sometimes even.

In this sentence it adds the second place:

• pošta i pekárna = literally something like the post office and also the bakery

In natural English, that often comes out simply as:

• the post office and the bakery

So i is not exactly the same as basic a (and), but in translation it can sometimes look very similar.

This is a very natural question.

You might expect plural jsou because English says the post office and the bakery are. But Czech can use singular je before a coordinated group like this, especially in everyday phrasing, where the sense is close to:

• where the post office is, and also the bakery

So kde je pošta i pekárna is understandable and natural in that kind of structure.

That said, learners may also encounter kde jsou pošta i pekárna, where the two nouns are treated more clearly as a plural subject. So the important thing is to recognize that Czech does not always match English agreement in exactly the same way here.

Because they are not objects here. They are the things whose location is being identified.

In the clause:

• kde je pošta i pekárna

the noun words are in the nominative form:

• pošta = post office
• pekárna = bakery

You can think of it as:

• the post office is...
• the bakery is...

So they stay in their base dictionary forms.

Because Czech does not have articles like English a/an/the.

So:

• mapa can mean a map or the map
• pošta can mean a post office or the post office
• pekárna can mean a bakery or the bakery

The exact meaning depends on context. In this sentence, English naturally uses a good map and the post office / the bakery, but Czech expresses that without separate article words.