Policie zná dobu krádeže.

Czech has no articles, so it does not use words like the or a/an.

So:

• Policie = the police / police
• dobu krádeže = the time of the theft

English needs articles here, but Czech usually does not.

Grammatically, policie is singular in Czech, which is why the verb is also singular: zná.

That can feel strange to English speakers, because English the police normally takes a plural verb:

• English: The police know
• Czech: Policie zná

Also, policie is grammatically feminine in Czech.

Zná is the 3rd person singular present tense form of znát.

So:

• znát = to know / be familiar with
• zná = he/she/it knows

Here it agrees with policie, which is singular:

• Policie zná = The police know

Because dobu is the accusative singular form of doba.

The noun doba is the direct object of zná, and direct objects often go in the accusative.

• nominative: doba
• accusative: dobu

So:

• Policie zná dobu...
• literally: The police know [the] time...

Because krádeže is in the genitive singular.

It depends on doba:

• doba čeho? = the time of what?
• doba krádeže = the time of the theft

So the structure is:

• dobu = accusative, because it is the object of zná
• krádeže = genitive, because it depends on doba

This is very common in Czech noun phrases.

In isolation, krádeže can have more than one grammatical use, but here it means genitive singular: of the theft.

Why not plural?

Because the phrase is doba krádeže, meaning the time of the theft. That relationship naturally calls for the genitive singular.

So in this sentence, it is understood as:

• krádeže = of the theft
• not thefts

That is a very natural question, because English often uses know for both.

In Czech, znát and vědět are different:

• vědět = to know a fact, to know that...
• znát = to know, be familiar with, know information such as a name, address, date, time, etc.

Czech often says things like:

• znát adresu = know the address
• znát jméno = know the name
• znát datum = know the date

So zná dobu krádeže is normal Czech.

In context, it usually means the time when the theft happened or the time frame of the theft, not necessarily the length of the theft in minutes.

So depending on context, it could mean:

• the exact time
• the approximate time
• the period during which it happened

In police or formal language, this kind of phrase is common.

No, Czech word order is more flexible than English, because the cases show the grammatical roles.

The neutral order here is:

• Policie zná dobu krádeže.

But other orders are possible for emphasis, for example:

• Dobu krádeže policie zná.

That might emphasize the time of the theft.

So the original sentence is a normal, straightforward order, but not the only possible one.

A simple pronunciation guide is:

PO-li-tsi-ye znaa DO-bu KRAA-de-zhe

A few notes:

• c in Czech sounds like ts
• zná has a long á
• doba has stress on the first syllable: DO-ba
• krádeže has ž, like the s in measure

Czech stress is usually on the first syllable of each word:

• POlicie
• ZNÁ
• DObu
• KRÁdeže

Not necessarily. It is capitalized here simply because it is the first word of the sentence.

In the middle of a sentence, policie would normally be lowercase unless it is part of an official name.

For example:

• Policie zná dobu krádeže.
• Mluvila s policií. = She spoke with the police.