Opravdu nechci přijít pozdě, protože v osm začíná kurz češtiny.

Opravdu means really. Here it strengthens the statement: the speaker is emphasizing that they really do not want to be late.

Putting it at the beginning is very natural in Czech when you want to stress the whole sentence:

• Opravdu nechci přijít pozdě. = I really don’t want to arrive late.

You could also hear:

• Nechci opravdu přijít pozdě.

but that sounds less neutral and may shift the emphasis slightly. Sentence-initial opravdu is the most straightforward choice here.

Nechci is the 1st person singular form of chtít (to want) in the present tense.

So:

• chci = I want
• nechci = I don’t want

The negation is made with ne- attached directly to the verb.

A few forms of chtít:

• chci = I want
• chceš = you want
• chce = he/she/it wants
• chceme = we want
• chcete = you (plural/formal) want
• chtějí / chcou = they want

So nechci přijít literally means I don’t want to come/arrive.

After chtít (to want), Czech normally uses an infinitive, just like English often uses to + verb:

• chci jít = I want to go
• chci spát = I want to sleep
• nechci přijít pozdě = I don’t want to arrive late

So the structure is:

• nechci
  • infinitive

Here:

• nechci = I don’t want
• přijít = to arrive / to come

Both can exist, but they are not exactly the same.

• přijít pozdě = to arrive late
• být pozdě = to be late

In this sentence, přijít pozdě is the more natural choice because the speaker is talking about arriving late to the course.

Compare:

• Nechci přijít pozdě. = I don’t want to arrive late.
• Už jsem pozdě. or Mám zpoždění / Jdu pozdě. = I’m already late.

So přijít pozdě focuses on the moment of arrival.

Because pozdě is an adverb, while pozdní is an adjective.

Here you need an adverb because it describes how someone arrives:

• přijít pozdě = to arrive late

Compare:

• pozdě = late, lately, at a late time (adverb)
• pozdní vlak = a late train / an evening train depending on context (adjective)

So after a verb like přijít, Czech uses the adverb:

• přijít brzy = arrive early
• přijít pozdě = arrive late

In Czech, protože (because) introduces a subordinate clause, and subordinate clauses are normally separated by a comma.

So:

• Opravdu nechci přijít pozdě, protože v osm začíná kurz češtiny.

This is standard Czech punctuation.

You will see the same with other subordinating conjunctions too:

• Vím, že přijde. = I know that he’ll come.
• Zůstanu doma, když bude pršet. = I’ll stay home if it rains.

Because when Czech expresses a specific clock time with v (at), it uses the accusative:

• v jednu = at one
• v pět = at five
• v osm = at eight

So v osm means at eight o’clock.

The form osmi is not used here. It belongs to other grammatical contexts, not this one.

You can also say:

• v osm hodin

but in everyday Czech, simply v osm is very common and natural.

Yes. Very often, Czech leaves out hodin when the meaning is obvious.

So these mean the same thing:

• v osm
• v osm hodin

The shorter version is extremely common in normal speech.

Similarly:

• ve tři = at three
• v šest = at six
• v deset = at ten

Both word orders are possible.

• V osm začíná kurz češtiny.
• Kurz češtiny začíná v osm.

Czech word order is more flexible than English. The difference is usually about emphasis and information structure, not basic grammar.

In v osm začíná kurz češtiny, the sentence starts with the time expression, so the time is foregrounded first. This is very natural if the important point is when the course starts.

Also, even though kurz češtiny comes after the verb, it is still the subject. Czech does not rely on word order as strictly as English does.

This is a good aspect question.

• začínat = imperfective
• začít = perfective

Here we have začíná, from začínat.

In Czech, the present tense of an imperfective verb can be used for scheduled or regular events:

• Film začíná v sedm. = The film starts at seven.
• Kurz začíná v osm. = The course starts at eight.

If you said začne, that is the future form of the perfective verb začít. It is possible in some contexts, but for timetables and scheduled events, začíná is very common and idiomatic.

So v osm začíná kurz češtiny sounds like a normal timetable statement: the Czech course starts at eight.

Češtiny is genitive singular of čeština.

• čeština = Czech (the language)
• kurz češtiny = course of Czech = Czech course

This is a very common Czech pattern: one noun is followed by another noun in the genitive to show type, content, or association.

Examples:

• učitel češtiny = teacher of Czech
• student medicíny = student of medicine
• sklenice vody = glass of water

So kurz češtiny literally means course of Czech.

Because Czech has no articles like English a/an/the.

So:

• kurz can mean a course or the course
• the exact meaning comes from context

In this sentence, English naturally says the Czech course or the Czech class/course, but Czech simply says kurz češtiny.

This is one of the biggest differences from English: Czech usually leaves definiteness unstated unless context, word order, or another expression makes it clear.

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

• nechci already tells you the subject is I
• so já is unnecessary unless you want extra emphasis

Compare:

• Opravdu nechci přijít pozdě. = neutral, natural
• Já opravdu nechci přijít pozdě. = I really don’t want to arrive late (extra emphasis on I)

This is very common in Czech:

• Jdu domů. = I’m going home.
• Máme čas. = We have time.

Yes. Czech allows several natural word orders, depending on emphasis.

For example:

• Opravdu nechci přijít pozdě, protože v osm začíná kurz češtiny.
• Protože v osm začíná kurz češtiny, opravdu nechci přijít pozdě.
• V osm začíná kurz češtiny, takže opravdu nechci přijít pozdě.
  (This changes because to so, so the structure is slightly different.)

The original version is very natural because it starts with the speaker’s concern and then gives the reason.

So the sentence order is not random, but it is more flexible than in English.