Tiskárna dnes zase nejde, proto ten soubor nemůžu vytisknout.

Tiskárna means printer. Here it is in the nominative singular because it is the subject of the sentence — the thing that isn’t working.

• Tiskárna dnes zase nejde = The printer isn’t working again today

Also, tiskárna is a feminine noun, which is why its dictionary form ends in -a.

Dnes means today.

Zase usually means again, but in everyday Czech it often has the feeling of:

• again
• once again
• yet again
• as usual, annoyingly again

So dnes zase nejde suggests something like:

• It’s not working again today
• Today it’s not working yet again

It often adds a slight feeling of frustration.

Yes, jít normally means to go, but in Czech it is also commonly used for machines, devices, programs, or systems to mean:

• to work
• to run
• to function

So:

• Tiskárna nejde = The printer isn’t working
• Počítač nejde = The computer isn’t working
• Internet nejde = The internet isn’t working

This is very common colloquial Czech.

A more explicitly technical version would be nefunguje (is not functioning), but nejde is extremely natural in speech.

The verb here is jít. Its 3rd person singular present form is jde:

• on/ona/ono jde = he/she/it goes / works

To make it negative, Czech adds ne-:

• jde → nejde

So:

• Tiskárna jde = The printer works
• Tiskárna nejde = The printer doesn’t work

This is a normal negative formation in Czech.

This is a very common point of confusion.

• proto = therefore / that’s why / for that reason
• protože = because

So in your sentence:

• Tiskárna dnes zase nejde, proto ten soubor nemůžu vytisknout.
• The printer isn’t working again today, therefore/that’s why I can’t print that file.

If you used protože, the logic would reverse:

• Nemůžu ten soubor vytisknout, protože tiskárna dnes zase nejde.
• I can’t print the file because the printer isn’t working again today.

So:

• proto introduces the result
• protože introduces the reason

Because the sentence contains two clauses:

1. Tiskárna dnes zase nejde
2. proto ten soubor nemůžu vytisknout

In Czech, clauses like this are normally separated by a comma. Here the comma helps mark the relationship:

• first clause = the problem
• second clause = the result

So the comma is standard and expected.

Ten soubor means that file or sometimes simply the file, depending on context.

Ten is a demonstrative word, literally that, but in everyday Czech it is often used more loosely than English that. It can simply point to a specific known item.

So:

• soubor = file
• ten soubor = that file / the particular file

It is not always necessary. You could say:

• proto soubor nemůžu vytisknout

But that sounds less natural in many everyday contexts. Czech often uses ten/ta/to where English might just use the.

It is in the accusative singular, because it is the direct object of vytisknout (to print).

The tricky part is that soubor is a masculine inanimate noun, and in the singular, the accusative often looks the same as the nominative.

So:

• nominative: ten soubor
• accusative: ten soubor

That is why you do not see a visible change here.

It is indeed from moci (can / to be able to).

The standard 1st person singular is:

• mohu = I can

But in everyday spoken Czech, the much more common form is:

• můžu = I can

So the negative becomes:

• nemohu = more formal/literary
• nemůžu = common spoken Czech

Both are correct, but nemůžu sounds very natural in conversation.

Because the sentence means I can’t print out / complete the printing of that file, not just I’m not printing.

Here are the differences:

• netisknu = I’m not printing / I don’t print
• nemůžu tisknout = I can’t be printing / I can’t print in a more ongoing, process-oriented sense
• nemůžu vytisknout = I can’t print it out / I can’t get it printed

Vytisknout is a perfective verb, which focuses on the action as a completed whole. That fits well here, because the speaker means they are unable to successfully produce the printed file.

This is an aspect question.

• tisknout = to print, imperfective
• vytisknout = to print out / to print successfully, perfective

Very roughly:

• tisknout focuses on the process, repetition, or general activity
• vytisknout focuses on the completed result

Examples:

• Tisknu dokument. = I’m printing a document.
• Vytisknu dokument. = I’ll print out the document / I’ll get it printed.

In your sentence, vytisknout is natural because the speaker cannot achieve the finished result.

Both are possible.

Czech word order is flexible and often reflects emphasis, topic, or what is already known in the conversation.

• proto ten soubor nemůžu vytisknout
• proto nemůžu ten soubor vytisknout

Both mean essentially the same thing.

The version with ten soubor earlier can give a little more prominence to that file as the thing being discussed. It may sound like:

• so that file I can’t print

Czech often moves elements around for emphasis in a way English usually does not.

Yes.

• Tiskárna dnes zase nejde
• Tiskárna dnes zase nefunguje

Both mean The printer isn’t working again today.

The difference is mostly in tone:

• nejde = very common, everyday, colloquial
• nefunguje = a little more explicit, slightly more formal or technical

A native speaker would understand either immediately.

It is mostly neutral everyday Czech, but it does include spoken-style choices:

• zase is very common in speech
• nejde for a machine not working is very everyday
• nemůžu is the normal spoken form instead of more formal nemohu

So the sentence sounds very natural in conversation and informal writing. It is not slang, but it is not especially formal either.

Yes, often very naturally.

• Tiskárna dnes zase nejde, proto ten soubor nemůžu vytisknout.
• The printer isn’t working again today, so I can’t print that file.

Although proto literally leans more toward therefore / for that reason, in smooth English so is often the best translation.