Zítra půjdu na úřad.

Jdu is the present tense form of jít: I am going / I go.

Půjdu is the future tense form: I will go.

With jít, Czech does not normally make the future with budu + infinitive. Instead, it has its own future form:

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

So in Zítra půjdu na úřad, půjdu is the natural way to say I will go.

Yes. Půjdu is the future form of jít.

This is one of those verbs where the forms are not very similar, so it has to be learned as an irregular pattern. Some key forms are:

• infinitive: jít = to go
• present: jdu = I go / I am going
• future: půjdu = I will go

So even though jít and půjdu do not look closely connected, they belong together.

Because Czech verbs usually already show the subject.

The ending in půjdu tells you it is first person singular, so I is already built into the verb. That means já is usually unnecessary.

You could say:

• Zítra půjdu na úřad.
• Já zítra půjdu na úřad.

Both are possible, but adding já usually gives extra emphasis, something like I will go tomorrow.

This is a very common learner question, because English often just uses to for both.

In Czech, both na and do can indicate movement to somewhere, but they are used with different places and patterns.

With institutions and events, Czech often uses na:

• na úřad = to the office / to the government office
• na poštu = to the post office
• na policii = to the police station
• na univerzitu = to university

Do is more typical for going into a building, area, or enclosed place:

• do domu = into the house
• do školy = to school / into the school building
• do města = to the city

So na úřad is simply the normal Czech expression.

It is in the accusative case.

The preposition na can take different cases depending on meaning:

• na + accusative = motion onto / to
• na + locative = location on / at

Here there is movement, so Czech uses na + accusative:

• na úřad = to the office

Compare:

• Jdu na úřad. = I am going to the office.
• Jsem na úřadě. = I am at the office.

So:

• úřad = nominative / dictionary form
• na úřad = accusative
• na úřadě = locative

Yes. Czech word order is quite flexible.

Zítra půjdu na úřad is a very natural neutral sentence, with zítra at the front to set the time.

You could also say:

• Půjdu zítra na úřad.
• Na úřad půjdu zítra.

These all mean roughly the same thing, but the focus changes a little:

• Zítra půjdu na úřad. = neutral, starting with tomorrow
• Půjdu zítra na úřad. = also neutral, slightly more centered on the action
• Na úřad půjdu zítra. = emphasizes to the office

So the original sentence is one of the most natural everyday word orders.

Usually, yes.

Jít often suggests going on foot or simply going in a general sense when the exact transport is not important.

If you want to emphasize travel by vehicle, Czech often uses jet instead:

• Půjdu na úřad. = I’ll go to the office. / I’ll walk there. / I’ll go there.
• Pojedu na úřad. = I’ll go to the office by vehicle.

In real life, půjdu can still be used even if the speaker is not literally walking the whole way, especially in casual speech. But the basic distinction is:

• jít / půjdu = go, usually on foot
• jet / pojedu = go by vehicle

Zítra means tomorrow, and here it functions as a time expression.

It does not have to come first, but putting it first is very common because it sets the time frame right away.

Compare:

• Zítra půjdu na úřad.
• Půjdu zítra na úřad.

Both are correct. Czech often puts time words early in the sentence, especially in neutral statements.

A rough pronunciation guide for an English speaker is:

• Zítra ≈ ZEE-tra
• půjdu ≈ POY-doo
• na ≈ nah
• úřad ≈ OO-rzhut or OO-rzhad depending on how carefully you say it

A few useful sound notes:

• í and ú are long vowels.
• ů is also a long u sound.
• j is pronounced like English y.
• ou sounds roughly like oh + oo blended together.
• ř is the famous Czech sound: something like a mix of r and zh. It takes practice.

So půjdu sounds something like POY-doo, and úřad contains the difficult ř sound.

Not usually. Úřad most often means an official office, especially a government or administrative office.

So this sentence usually suggests something like going to:

• a municipal office
• an administrative office
• an authority or government department

For a regular business office, Czech often uses kancelář instead.

So na úřad has a more official, bureaucratic feel than just to the office in English.

No, that would not be standard Czech.

For jít, the future is not formed with budu + infinitive. You should use the special future form půjdu.

Correct:

• Zítra půjdu na úřad.

Not standard:

• Zítra budu jít na úřad.

This is an important pattern to memorize with verbs of motion.