Learn Hardcore Czech: Dnes mám dobrou náladu, protože je pátek a práce skončila. - Today I am in a good mood because it is Friday and work is over.

The basic form is dobrá nálada = good mood (nominative, feminine singular).
In the sentence mám dobrou náladu (I have a good mood), náladu is the direct object of the verb mám (I have), so it must be in the accusative case.
Feminine singular accusative of dobrá is dobrou, and of nálada is náladu.

So:

nominative: dobrá nálada (subject)
accusative: dobrou náladu (object)

Why do Czechs say mám dobrou náladu (“I have a good mood”) instead of something like “I am in a good mood”?

Czech often uses mít (to have) to express temporary states that English expresses with to be.

Typical patterns:

Mám hlad. – I am hungry. (literally: I have hunger.)
Mám žízeň. – I am thirsty.
Mám radost. – I am glad / I’m happy about it.
Mám dobrou náladu. – I am in a good mood.

You can say jsem v dobré náladě, and it is grammatically correct, but:

mám dobrou náladu is more neutral and common.
jsem v dobré náladě can sound a bit more formal or slightly more “language‑bookish” in everyday speech.

Why is there a comma before protože?

Protože (because) introduces a subordinate clause (a reason clause). In Czech, subordinate clauses are normally separated from the main clause by a comma.

Main clause: Dnes mám dobrou náladu
Subordinate clause: protože je pátek a práce skončila

So you write:
Dnes mám dobrou náladu, protože je pátek a práce skončila.

However, notice that there is no comma before a inside the protože clause:

protože je pátek a práce skončila
Here a (and) just joins two parts of the same clause:
je pátek
- práce skončila.

Why is it just je pátek and not something like “it is the Friday” or “it is a Friday”?

Czech has no articles (a / an / the). You simply say:

Je pátek. – It is Friday.
Je pondělí. – It is Monday.
Je léto. – It is summer.
Je večer. – It is evening.

The context usually makes it clear whether English would use a or the. So je pátek always corresponds to “it is Friday” in the natural English way, without specifying “a” or “the”.

Can I omit je and say just protože pátek?

No, you cannot omit je here. You need the verb být (to be):

Correct: protože je pátek – because (it) is Friday
Incorrect: protože pátek

In sentences stating the day, date, time, or similar, Czech normally uses je:

Je pátek.
Je deset hodin. – It is ten o’clock.
Je prvního ledna. – It’s the first of January.

So je is necessary as the linking verb.

What is the role of práce in práce skončila? Is it the subject, even though it looks like “work finished”?

Yes, práce (work, job) is the subject of the verb skončila.

práce – feminine, nominative singular
skončila – past tense, 3rd person singular, feminine (agrees with práce)

Literally: práce skončila = the work has finished / the work ended.
Czech allows this structure without any extra pronoun like “it”; práce itself is the subject.

Why skončila and not skončila se, končila, or something else?

Here are the main points:

Aspect: skončit vs. končit
- skončit = perfective, to finish / to come to an end (completed event).
- končit = imperfective, to be ending / to usually end / to be in the process of ending.
- práce skončila → the work has finished (it’s over now).
- práce končila would focus more on the process or on repetition (e.g. work was ending / used to end at some time).
Reflexive form: skončit se
- There is also reflexive skončit se = to come to an end (by itself), but in many contexts skončit and skončit se are interchangeable.
- Here, práce skončila is perfectly natural and common. práce se skončila sounds marked or regionally coloured in many dialects and is not needed.

So práce skončila is the normal, standard way to say work is finished / work has ended.

What is the gender and case of práce here?

In this sentence:

práce is feminine.
It is in the nominative singular (the basic “dictionary” form).
It functions as the subject of the verb skončila.

In Czech, práce has the same form for nominative and genitive singular, but:

here we know it’s nominative because it is the thing that “finished”.

Why does skončila end in -a?

The ending -a shows agreement with a feminine singular subject in the past tense.

Czech past tense is formed from the past participle, which agrees with gender and number:

masculine inanimate sg.: skončil
masculine animate sg.: skončil
feminine sg.: skončila
neuter sg.: skončilo
plural (mixed / masc. animate): skončili
plural (fem. only or non‑masc.): skončily

Since práce is feminine singular, you must say:

práce skončila.

Why does the sentence start with Dnes? Could I say Mám dnes dobrou náladu instead?

Yes, you can say Mám dnes dobrou náladu. Both are correct, but the word order slightly changes the emphasis.

Dnes mám dobrou náladu…
– Starts with Dnes (Today), so it sets the time as the topic: Today, (as for today), I’m in a good mood…
Mám dnes dobrou náladu…
– Starts with Mám (I have), so it feels more like a neutral statement about you, with dnes as a detail: I am in a good mood today…

Czech word order is relatively flexible. Typically:

Time adverbs like dnes often come at the beginning or before the verb, but both positions here are completely natural.

What’s the difference between dnes and dneska?

Both mean today and are very common.

dnes – slightly more neutral or a bit more formal; fine in both speech and writing.
dneska – more colloquial and conversational; extremely common in everyday speech.

You could replace in the sentence:

Dnes mám dobrou náladu…
Dneska mám dobrou náladu…

Both are correct; dneska just feels a bit more informal.

Why is there no já (I) before mám?

Czech usually omits subject pronouns when they are clear from the verb ending.

mám already shows 1st person singular (I have).
So já mám dobrou náladu is grammatically correct, but it is only used when you want to emphasize “I”:
- Já mám dobrou náladu, ale on ne. – I‘m in a good mood, but he isn’t.

In neutral statements, you just say:

Mám dobrou náladu. – I’m in a good mood.

Why is náladu in that form and not nálada?

Nálada is a feminine noun. Its basic (nominative singular) form is nálada.

In mám dobrou náladu:

náladu is the direct object of mám.
Direct objects without prepositions are normally in the accusative case.
Feminine singular accusative of nálada is náladu.

So:

nominative: nálada – the mood (as a subject)
accusative: náladu – the mood (as an object)
→ Mám dobrou náladu.

Is the word order inside protože je pátek a práce skončila fixed, or can I change it?

There is some flexibility, but not everything is equally natural.

Most natural:

protože je pátek a práce skončila – because it is Friday and work has finished.

Also possible:

protože je pátek a skončila práce – same meaning, just a slightly different rhythm/emphasis.

Less natural or wrong patterns:

protože pátek je a práce skončila – sounds odd in standard Czech; the je usually comes before pátek here.
protože pátek je a skončila práce – still strange.

So the safest and most idiomatic is exactly what you have:

protože je pátek a práce skončila.