Learn Hardcore Czech: Angličtina je jazyk, který používám v práci nejčastěji. - English is the language that I use at work most often.

Angličtina je jazyk… can mean:
- “English is a language that I use most often at work.” or
- “English is the language that I use most often at work.”

The context decides whether English corresponds to “a” or “the”; the Czech sentence itself does not mark this difference.

Why is there a comma before který?

In Czech, you normally put a comma before a relative clause introduced by který, co, jenž etc.

Angličtina je jazyk, který používám v práci nejčastěji.
- Main clause: Angličtina je jazyk
- Relative clause: který používám v práci nejčastěji

So the comma separates the main clause from the relative clause, similar to:
“English is the language that I use most often at work.”

Why is it který and not která, when angličtina is feminine?

The relative pronoun který refers to jazyk, not to angličtina.

jazyk = masculine inanimate noun → nominative singular masculine = který
If the antecedent were feminine, you would use která; for neuter, které, etc.

So the structure is:

Angličtina (subject, feminine) je jazyk (predicative noun, masculine) , který… (referring to jazyk).

What exactly does který používám v práci nejčastěji mean literally?

Word‑for‑word:

který – which / that
používám – I use
v práci – at work / in (my) job
nejčastěji – (the) most often

So literally: “…a language which I use at work most often.”

Can I change the word order, e.g. který nejčastěji používám v práci or který používám nejčastěji v práci?

Yes, Czech word order is fairly flexible, and all of these are grammatical:

který používám v práci nejčastěji (neutral, as given)
který nejčastěji používám v práci (slight emphasis on how often)
který používám nejčastěji v práci (emphasis that “most often” is specifically at work)

They all basically mean the same thing; differences are mainly in focus/emphasis, not in grammar.

Why is it používám and not another verb like mluvím or užívám?

používat = to use (very common and neutral)
- používám angličtinu v práci – I use English at work
mluvit = to speak
- mluvím anglicky v práci – I speak English at work
užívat can also mean “to use” but is more formal or in specific contexts (medicine, rights, enjoyment).

In the given sentence, you’re talking about the language you use (for communication, tasks, etc.), so používat is the natural, general verb.

What is the function of nejčastěji? How is it formed?

nejčastěji is the superlative form of the adverb často (often).

často – often
častěji – more often (comparative)
nejčastěji – most often (superlative)

It modifies the verb používám:

používám nejčastěji – I use (it) most often

Note the difference:

nejčastější jazyk – the most frequent language (adjective)
používat nejčastěji – to use most often (adverb)

Why is it v práci and not something like na práci?

v práci (locative) = at work / at my job, describing the place/situation where you work.
- Používám angličtinu v práci. – I use English at work.
na práci would mean “on (the) work / for work (as a task)”, and is used in different contexts:
- Mám málo času na práci. – I have little time for work.
- Nástroj na práci. – A tool for work.

So v práci is the idiomatic way to say “at work”.

Is v práci a particular case form? Which case is it?

Yes:

práce (work, job) – basic form (nominative singular)
v práci – locative singular after the preposition v (“in/at”)

Prepositions in Czech always require a specific case; v with location (where?) normally uses the locative:
v práci, v kanceláři, ve škole.

Why is Angličtina capitalized? Are language names always capitalized in Czech?

Here Angličtina is capitalized only because it is the first word of the sentence.

By standard Czech spelling rules:

Names of languages are written with lowercase: angličtina, čeština, němčina.
At the start of a sentence, the first letter is capitalized:
- Angličtina je jazyk…

So in the middle of a sentence you would write: Mluvím angličtinou.

Why is there no já (“I”) before používám?

In Czech, the subject pronoun is usually dropped because the verb ending shows the person:

používám → 1st person singular (I use)
So který používám v práci nejčastěji already means “which I use most often at work”.

You would only add já for emphasis or contrast:

…který používám v práci nejčastěji já (a ne kolegové).
“…which I use most often at work (and not my colleagues).”

Could I say the same idea without the relative clause, like Angličtinu používám v práci nejčastěji?

Yes. These are both correct but slightly different in structure:

Angličtinu používám v práci nejčastěji.
- Literally: “I use English at work most often.”
- Simple statement, English is in direct object position (accusative).
Angličtina je jazyk, který používám v práci nejčastěji.
- Literally: “English is the language that I use at work most often.”
- More explicit definition of English as the language in question.

Meaning is very close; (2) sounds a bit more formal/explicit.

Could I remove jazyk and say Angličtina je to, co používám v práci nejčastěji?

You can, and it is grammatical:

Angličtina je to, co používám v práci nejčastěji.
– “English is what I use most often at work.”

Differences:

…je jazyk, který… – explicitly labels English as a language.
…je to, co… – more general and a bit more colloquial/indirect: “English is the thing that I use…”.

Both are understandable; the original is clearer that you are classifying English specifically as a language.

What tense/aspect is používám, and why is it present tense if we talk about habits?

používám is:

Present tense
1st person singular
Imperfective aspect (ongoing/repeated actions)

In Czech, the present tense of an imperfective verb is used for general truths, habits, and repeated actions, just like the English present simple:

Každý den používám počítač. – I use the computer every day.
Angličtina je jazyk, který používám v práci nejčastěji. – English is the language that I use most often at work.

So the tense-aspect choice is fully natural for describing a regular habit.