Rozhodnutí o dopravním přestupku je v dopise.

Here rozhodnutí means decision, ruling, or official decision.

A few useful notes:

• It is a neuter noun.
• It comes from the verb rozhodnout / rozhodovat, meaning to decide.
• In official or administrative language, rozhodnutí often refers to a formal decision issued by an authority.

So in this sentence, it sounds quite natural as an official document-related phrase.

Because the preposition o in this meaning takes the locative case.

Here o means something like:

• about
• concerning
• regarding

The base phrase is:

• dopravní přestupek = traffic offense / traffic violation

After o, it changes to locative singular:

• dopravní přestupek → o dopravním přestupku

Both words change as needed:

• dopravní → dopravním
• přestupek → přestupku

Because adjectives in Czech must agree with the noun they describe in:

• gender
• number
• case

The noun přestupek is:

• masculine inanimate
• singular
• here in the locative

So the adjective has to match it:

• dopravní přestupek
• o dopravním přestupku

That -ím ending is the locative singular ending for this adjective pattern with a masculine inanimate noun.

Because v meaning in normally takes the locative case when it expresses location.

The base noun is:

• dopis = letter

In the locative singular:

• dopis → dopise

So:

• v dopise = in the letter

Because v dopise means the information is inside the letter / in the text of the letter.

By contrast, na dopise would usually mean on the letter, more like on its physical surface. That would sound more like talking about writing, marks, or an address on the outside.

So in this sentence:

• v dopise = the decision is contained in the letter

Yes.

The structure is:

• Rozhodnutí o dopravním přestupku = the subject
• je = is
• v dopise = in the letter

So literally the sentence is:

• The decision regarding the traffic offense is in the letter.

Even though rozhodnutí has the same form in nominative and accusative, here it is clearly the subject because it is the thing being identified as being in the letter.

Yes. In standard Czech, the present-tense form of být = to be is normally expressed.

So:

• je = is

Unlike some Slavic languages where the present-tense to be can be omitted, Czech normally keeps it in sentences like this.

So Rozhodnutí o dopravním přestupku v dopise would sound incomplete if you wanted to say The decision ... is in the letter.

Yes. Czech word order is quite flexible, but changing it usually changes the focus or emphasis.

This sentence:

• Rozhodnutí o dopravním přestupku je v dopise.

sounds fairly neutral if you are talking about the decision and then saying where it is.

You could also say:

• V dopise je rozhodnutí o dopravním přestupku.

That puts more emphasis on where it is: In the letter, there is the decision...

So both are possible, but they do not feel exactly identical in emphasis.

Not exactly.

Dopravní přestupek means:

• traffic offense
• traffic violation
• traffic infraction

It refers to the violation itself, not the paper you receive.

A ticket, fine, or official notice would be something else, depending on context, for example:

• pokuta = fine
• oznámení = notice
• rozhodnutí = decision/ruling

So this sentence is about the decision concerning the offense, not the offense itself and not necessarily a physical ticket.

Because of the verb:

• je = is → singular
• jsou = are → plural

This matters because rozhodnutí has the same form in some singular and plural cases.

So:

• Rozhodnutí ... je ... = The decision ... is ...
• Rozhodnutí ... jsou ... = The decisions ... are ...

The verb tells you the number here.

Yes, it sounds fairly formal or administrative.

Words like:

• rozhodnutí
• dopravní přestupek

are very common in official Czech, especially in legal, bureaucratic, or police-related contexts.

In everyday casual conversation, people might say something simpler depending on context, but this sentence sounds natural for official correspondence.