Po práci půjdu i na poštu.

Po práci means after work. In Czech, expressions of time often come near the beginning of the sentence to set the scene first.

So Po práci půjdu i na poštu is very natural because it first tells you when the action happens, and then says what the speaker will do.

A very literal breakdown is:

• Po práci = after work
• půjdu = I will go
• i = also / too
• na poštu = to the post office

Because the preposition po requires the locative case here.

The basic form is:

• práce = work

But after po in the sense of after, it changes to:

• po práci = after work

So this is a case change:

• nominative: práce
• locative: práci

This is something you will see often in Czech: prepositions often force a noun into a specific case.

In a word-for-word sense, yes, but Czech does not use articles like a or the.

So po práci can correspond to English after work, after the work, or sometimes after my work, depending on context.

In this sentence, the natural English meaning is simply after work.

Because půjdu is the future tense of jít.

• jdu = I am going / I go
• půjdu = I will go

So if the speaker is talking about something they plan to do later, Czech uses půjdu.

This verb is a bit irregular, so it is worth learning as a set:

• jdu = I go / I am going
• půjdu = I will go

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

Here, půjdu already means I will go, so adding já is unnecessary.

• Půjdu i na poštu. = I’ll also go to the post office.
• Já půjdu i na poštu. = I will also go to the post office.

The version with já is possible, but it gives extra emphasis, like I will go too.

Here i means also, too, or sometimes even, depending on context.

In Po práci půjdu i na poštu, it most naturally means also:

• I’ll also go to the post office after work.

Because i stands right before na poštu, it especially connects to that part of the sentence: the speaker is saying that going to the post office is one more thing they will do.

Compare:

• Půjdu na poštu. = I’ll go to the post office.
• Půjdu i na poštu. = I’ll also go to the post office.

Because Czech idiomatically says jít na poštu for go to the post office.

With places in Czech, the choice of preposition is not always the same as in English, so you often have to learn the usual combination:

• na poštu = to the post office
• na poště = at the post office

Even though English says to the post office, Czech uses na here.

This is similar to other common expressions where Czech uses na with destinations:

• na nádraží = to the station
• na univerzitu = to the university
• na policii = to the police station / police

Because na takes the accusative case when it expresses movement toward a destination.

Here the speaker is going somewhere:

• na poštu = to the post office

The noun changes like this:

• nominative: pošta
• accusative: poštu

A useful contrast is:

• Jdu na poštu. = I am going to the post office.
  
  • movement, so accusative
• Jsem na poště. = I am at the post office.
  
  • location, so locative

Yes. Czech word order is fairly flexible, but changing it can shift the emphasis.

The original sentence:

• Po práci půjdu i na poštu.

sounds natural and neutral.

Other possible versions include:

• I na poštu půjdu po práci.
• Půjdu po práci i na poštu.

These are grammatically possible, but they may sound more marked or put emphasis on a different part of the sentence.

As a learner, the original order is a very good model:

• time expression first
• verb next
• extra focused element later

Půjdu is pronounced approximately POO-y-doo.

A few details:

• ů sounds like a long oo
• j sounds like English y
• du sounds roughly like doo

So:

• pů ≈ poo
• j ≈ y
• du ≈ doo

Put together: POO-y-doo

Also, the stress in Czech normally falls on the first syllable, so the stress is on půj-.