Platnost povolení skončí zítra.

• platnost = validity, period of validity, or effectiveness. It is the head noun of the subject.
• povolení = permit, license, or authorization. Here it depends on platnost.
• skončí = will end / will expire. This is the verb.
• zítra = tomorrow. This is a time adverb.

So the whole subject is platnost povolení = the validity of the permit, and the verb says that this validity will end tomorrow.

Because platnost commonly takes the genitive: platnost čeho? = the validity of what?

So:

• platnost povolení = the validity of the permit
• platnost dokumentu = the validity of the document
• platnost smlouvy = the validity of the contract

The noun povolení is a neuter noun, and in this pattern its genitive singular happens to look the same as its nominative singular: povolení.

That is why the form does not visibly change here.

Platnost is in the nominative singular, because it is the grammatical subject of the sentence.

You can think of the structure as:

• Platnost povolení = subject
• skončí = verb
• zítra = adverb of time

Even though English often says The permit expires tomorrow, Czech here literally says The validity of the permit will end tomorrow.

This is mainly about aspect.

• skončit is perfective
• končit is imperfective

In Czech, a perfective present form usually refers to the future. So:

• skončí = will end
• not ends in the ordinary present-time sense

That is why skončí zítra naturally means will end tomorrow.

If you said končí zítra, that can also be possible in some contexts, especially for something scheduled or imminent, but skončí is very natural when you mean the endpoint itself.

Formally, yes: it is the present-tense form of a perfective verb. But in meaning, it refers to the future.

This is a very important Czech pattern:

• imperfective present = true present
• perfective present = future meaning

Examples:

• končí = is ending / ends
• skončí = will end

So in practice, learners usually just remember that perfective present forms often translate as English future.

Because Czech has no articles like English a or the.

So:

• platnost povolení can mean the validity of the permit
• or sometimes validity of a permit, depending on context

The listener figures out definiteness from the situation, not from an article.

It is natural, but it sounds somewhat official, administrative, or written.

You would often see this kind of wording in:

• letters from offices
• permit notices
• legal or bureaucratic documents
• website instructions

In everyday speech, people might also say:

• Povolení zítra skončí.
• Povolení vyprší zítra.
• Povolení končí zítra.

These are a bit more direct or conversational, depending on context.

They are close, but not identical.

• Platnost povolení skončí zítra focuses on the validity period
• Povolení skončí zítra focuses more directly on the permit itself

In many practical situations, both communicate almost the same thing. But the version with platnost is more precise and bureaucratic, because it explicitly talks about the permit’s period of validity.

A very common alternative is:

• Platnost povolení vyprší zítra.

That often sounds even more specifically like the permit expires tomorrow.

Yes. Czech word order is flexible, and changing it usually changes emphasis, not the core meaning.

Possible variants:

• Platnost povolení skončí zítra.
• Zítra skončí platnost povolení.
• Platnost povolení zítra skončí.

All of these can work.

Very roughly:

• starting with zítra emphasizes tomorrow
• ending with zítra gives it a more neutral informational flow
• putting zítra before the verb can also sound natural, depending on rhythm and context

Here zítra is best treated as an adverb of time meaning tomorrow.

For learners, the important point is:

• it does not need a preposition
• it answers when?
• it modifies the verb skončí

So:

• skončí kdy? → zítra

A simple pronunciation guide:

• Platnost → roughly PLAT-nost
• povolení → roughly PO-vo-le-nee
• skončí → roughly SKON-chee
• zítra → roughly ZEE-tra

A few helpful points:

• Czech stress is usually on the first syllable of each word.
• č sounds like ch in church
• í is a long ee sound

So the whole sentence is approximately:

PLAT-nost PO-vo-le-nee SKON-chee ZEE-tra

Yes, absolutely, and it is very common.

Difference in nuance:

• skončí = will end
• vyprší = will expire

When talking about documents, permits, deadlines, memberships, and validity periods, vypršet is often especially natural.

So:

• Platnost povolení skončí zítra = correct and natural
• Platnost povolení vyprší zítra = also correct, and often even more idiomatic for official validity

Yes. Even though Czech uses skončí, English often prefers the simple present for scheduled or fixed future events:

• The permit expires tomorrow
• The validity of the permit expires tomorrow
• The permit will expire tomorrow

All of these can match the Czech sentence well, depending on style.

So when learning Czech, do not expect a one-to-one tense match with English. Czech and English often package future meaning differently.

A good summary is:

1. platnost + genitive

   • platnost povolení = validity of the permit

2. perfective verb in present form = future meaning

   • skončí = will end

3. zítra is a simple time adverb

   • tomorrow

So a useful model is:

[Noun in nominative] + [dependent noun in genitive] + [perfective present verb] + [time expression]

Example:

• Platnost pasu skončí příští měsíc.
• The passport’s validity will end next month.