Learn Hardcore Czech: Můj syn má rád jasné dny, ale dnes nechce dělat nic, jenom sedí u počítače. - My son likes bright days, but today he doesn't want to do anything, he just sits at the computer.

syn = masculine singular
The masculine singular form of „my“ is můj.
moje is used for feminine singular (e.g. moje sestra) and for most neuter singular nouns (e.g. moje auto) in the basic (nominative) form.

So:

můj syn – my son
moje dcera – my daughter
moje dítě – my child

What does „má rád“ literally mean, and why not just say one word like „miluje“?

má rád is literally „has in a liked way“, but idiomatically it just means „likes“.

mít rád + noun = to like something or someone
- Můj syn má rád jasné dny. – My son likes bright days.

milovat = to love, and is much stronger, often emotional or romantic:

Miluju svoji ženu. – I love my wife.
Miluju hudbu. – I love music. (very strong liking)

So in everyday speech:

má rád jasné dny = natural, neutral „likes bright days“
miluje jasné dny = sounds stronger, more emotional or emphatic.

Why is it „má rád jasné dny“ and not something like „rád má jasné dny“?

The neutral word order is:

[subject] + [verb] + [object]
Můj syn má rád jasné dny.

You can move words for emphasis, but it changes the focus:

Jasné dny má rád můj syn. – Emphasizes who likes bright days (my son, not someone else).
Můj syn jasné dny má rád. – Slightly marked, stressing that it’s bright days that he likes.

But „rád má jasné dny“ is not idiomatic. The phrase mít rád should stay together as a unit: má rád.

What grammatical form is „jasné dny“ here, and why that ending?

The verb mít rád takes its object in the accusative case (like „to like something“).

den – day (masculine inanimate, singular, nominative)
dny – days (masculine inanimate, plural, nominative/accusative)
jasný den – bright day
jasné dny – bright days (accusative plural)

For masculine inanimate plural, the nominative and accusative of adjectives look the same: jasné.

So „jasné dny“ is accusative plural (object of „má rád“).

I’ve also seen „dni“ instead of „dny“. Why is it „dny“ here?

Both dny and dni are correct plurals of den, but:

dny is the normal modern form in everyday Czech.
dni sounds more formal, archaic, or poetic and is often used in set phrases or stylistic contexts.

In a neutral, conversational sentence like this, dny is the natural choice:

Můj syn má rád jasné dny. – standard, neutral
… jasné dni. – possible, but sounds literary/old-fashioned.

Where can I put „dnes“ in the sentence? Is „ale dnes nechce…“ the only option?

Czech word order is flexible, so dnes can move, but the neutral version here is:

Můj syn má rád jasné dny, ale dnes nechce dělat nic…

Other possible positions (with slight nuance):

Dnes můj syn nechce dělat nic… – slight emphasis on „today“.
Můj syn dnes nechce dělat nic… – also natural; „today my son doesn’t want to do anything“.

Putting dnes after the verb is also possible:

… ale nechce dnes dělat nic… – focuses a bit more on the verb than on „today“.

All of these are grammatical; they only slightly change the emphasis.

Why is it „nechce dělat nic“ and not „nechce dělat něco“?

In negative sentences, Czech tends to use „nic“ (nothing) rather than „něco“ (something).

chce dělat něco – he wants to do something
nechce dělat nic – he doesn’t want to do anything / he wants to do nothing

Using něco in a negative sentence (nechce dělat něco) would mean something like:

„He doesn’t want to do a certain something (specific thing)“
and would need context.
In general, to say „not … anything“, Czech prefers ne + nic.

I’ve also heard „nechce nic dělat“. Is that different from „nechce dělat nic“?

Both are correct and very common:

nechce dělat nic
nechce nic dělat

The difference is only in emphasis:

nechce dělat nic – slightly more neutral; focus on the fact that he doesn’t want to do anything.
nechce nic dělat – can emphasize „nothing“ a bit more („He doesn’t want to do anything at all“).

In everyday speech, both are used almost interchangeably.

What’s the difference between „jen“ and „jenom“ in „jenom sedí u počítače“?

jen and jenom both mean „only/just“ and are usually interchangeable.

jen – slightly shorter, often a bit more colloquial or clipped.
jenom – slightly fuller form; very common and neutral.

You could say:

… nechce dělat nic, jen sedí u počítače.
… nechce dělat nic, jenom sedí u počítače.

Both are fine, and most speakers alternate between them without thinking.

Why is it „sedí“ (simple present) when in English we say „is sitting“?

Czech does not have a separate continuous/progressive tense like English (is sitting, is doing).

The present tense in Czech covers both:

sedí = he sits / he is sitting
dělá = he does / he is doing

So:

… jenom sedí u počítače. can mean:
- „He just sits at the computer.“ (habitually)
- „He is just sitting at the computer (right now).“

Context decides whether you understand it as a general habit or a current action. Here, because of „dnes“, it is naturally understood as „is sitting today / right now“.

Why do we say „u počítače“ and not „na počítači“?

Prepositions in Czech are quite specific:

u (+ genitive) = at / by / near
- u stolu – at the table
- u okna – by the window
- u počítače – at the computer (sitting at the desk/computer)
na (+ locative) = on / on top of, sometimes at (events/activities)
- na stole – on the table
- na židli – on the chair
- na koncertě – at the concert

So „sedí u počítače“ correctly means „he is sitting at the computer“, not literally on top of it.
„sedí na počítači“ would literally be „he is sitting on the computer“ (physically on the device).

Why is „počítače“ in that form? What case is it?

The preposition „u“ always takes the genitive case.

počítač – computer (masculine inanimate, singular, nominative)
počítače – genitive singular (also nominative plural, but here it’s genitive singular)

So:

u + počítač → u počítače (at the computer)

The same pattern:

u domu – at the house (dům → domu)
u školy – at the school (škola → školy)
u kamaráda – at a friend’s (kamarád → kamaráda)

Why is there a comma before „ale“ and also before „jenom sedí u počítače“?

In Czech punctuation:

Comma before „ale“:
ale („but“) joins two clauses; you usually put a comma before it:
- Můj syn má rád jasné dny, ale dnes nechce dělat nic…
Comma before „jenom sedí u počítače“:
After „… nechce dělat nic“ you have another clause added with „jenom“ („only/just“). The comma separates the two parts:
- … dnes nechce dělat nic, jenom sedí u počítače.

So the sentence has three main pieces:

Můj syn má rád jasné dny,
ale dnes nechce dělat nic,
jenom sedí u počítače.

Each break is marked with a comma where a new clause starts.