Learn Hardcore Czech: Můj syn ještě spí v pokoji a nechce jít do školy. - My son is still sleeping in the room and does not want to go to school.

ještě = still, not yet finished
- Ještě spí. – He is still sleeping.
už = already / no longer
- Už spí. – He is already asleep.
- Už nespí. – He is no longer asleep / He isn’t sleeping anymore.

In questions, ještě can correspond to still and už to already:

Ještě spíš? – Are you still sleeping?
Už spíš? – Are you sleeping already? / Are you asleep yet?

So here, ještě tells us the sleeping is continuing and has not stopped yet.

Why is ještě between syn and spí? Can I move it to another place, like Můj syn spí ještě v pokoji?

Czech word order is relatively flexible, and adverbs like ještě can move. All of these are grammatically correct, but have slightly different emphasis:

Můj syn ještě spí v pokoji.
Neutral, most common. Focus is on the fact that he still sleeps.
Můj syn spí ještě v pokoji.
Slightly unusual here; it can sound like you are contrasting where he still sleeps (e.g. He still sleeps in the room (and not in his own apartment yet)).
Ještě můj syn spí v pokoji.
Now ještě is emphasized; could sound like: My son is still sleeping in the room (can you believe it?). More expressive, not the usual neutral order.

So the original Můj syn ještě spí v pokoji is the natural, neutral word order when you just want to say He is still sleeping in the room.

Why is it spí and not something like spá? How is the verb spát conjugated?

The infinitive is spát = to sleep.
In the present tense it changes to the -í pattern:

já spím – I sleep / I am sleeping
ty spíš – you sleep
on / ona / ono spí – he / she / it sleeps
my spíme – we sleep
vy spíte – you (plural / formal) sleep
oni spí – they sleep

So syn spí = (my) son is sleeping.

The vowel á in spát changes to í in the present-tense forms (spím, spíš, spí…). That is a normal pattern for many Czech verbs ending in -át (e.g. brát → beru, psát → píšu, etc.), although each verb may have its own specific changes.

Why is it v pokoji and not v pokoj? What is this -i ending?

The noun pokoj (room) is masculine inanimate. After the preposition v meaning in, when it expresses location (where something is), Czech uses the locative case.

Declension of pokoj (singular, most important forms):

Nominative (who/what?): pokoj – a room
Genitive (of whom/what?): pokoje
Dative (to whom/what?): pokoji
Accusative (whom/what?): pokoj
Locative (about/in whom/what?): pokoji
Instrumental (with whom/what?): pokojem

After v in the sense of in (location), we use the locative:

v pokoji = in the room

So v pokoj would be grammatically wrong; you must use the locative form pokoji.

Why is it do školy and not do škola? Which case is školy?

The noun škola (school) is feminine. The preposition do (meaning to / into in the directional sense) requires the genitive case.

Singular of škola:

Nominative: škola – (a/the) school
Genitive: školy – of a school / to (into) school (after do)
Dative: škole
Accusative: školu
Locative: škole
Instrumental: školou

After do with movement (to a place), you use genitive:

do školy = to (the) school

So do škola would be incorrect in standard Czech; you need the genitive form školy.

What is the difference between do školy and ve škole?

They use different prepositions and different cases, and they express different ideas:

do školy
- do
  - genitive (školy)
- Direction / movement: to (the) school
- Example: Jdu do školy. – I am going to school.
ve škole
- v / ve
  - locative (škole)
- Location / being somewhere: at school / in school
- Example: Jsem ve škole. – I am at school.

In your sentence nechce jít do školy, the action is going to school, so the directional phrase do školy is correct.

Why is the verb jít used here, and not chodit? Both can mean to go, right?

Yes, both refer to going on foot, but they differ in aspect and meaning:

jít – to go (one specific movement, now or in the near future)
- Nechce jít do školy. – He doesn’t want to go (this time / today) to school.
chodit – to go regularly / habitually; repeated actions
- Nechce chodit do školy. – He doesn’t want to go to school (in general, regularly; he doesn’t want to attend school).

In your sentence, jít do školy suggests a specific instance of going (for example, this morning). If you wanted to say he refuses school in general, you would use chodit do školy.

What does nechce mean exactly? How is it formed from chtít?

The verb chtít = to want is irregular.

Present tense (affirmative):

já chci – I want
ty chceš – you want
on / ona / ono chce – he / she / it wants
my chceme – we want
vy chcete – you (pl./formal) want
oni chtějí – they want

To make it negative, you add ne- in front of the verb:

nechci – I don’t want
nechceš – you don’t want
nechce – he / she / it doesn’t want
etc.

So nechce = (he) doesn’t want.

In the sentence, nechce jít literally is (he) doesn’t want to go (modal verb chtít + infinitive jít).

Why don’t we need a word like English to before jít in nechce jít?

Czech does not use a separate word like English to before infinitives. The form jít is already the infinitive (to go).

So:

nechce jít
Literally: does not-want go
Meaning: doesn’t want to go

Typical pattern: modal or similar verb + infinitive, with no extra particle:

musí jít – he must go / has to go
může jít – he can go
chce spát – he wants to sleep
nechce jít – he doesn’t want to go

Could I say Ještě můj syn spí v pokoji instead? How does that sound?

You can, but it changes the nuance.

Můj syn ještě spí v pokoji.
Neutral: My son is still sleeping in the room.
Ještě můj syn spí v pokoji.
More marked: My son is still sleeping in the room.
This version emphasizes ještě more strongly, like a comment or complaint:
He is still sleeping (believe it or not / which is surprising).

So the second version sounds more expressive, less neutral; it could fit in spoken conversation when you want to stress the still.

Why is it Můj syn at the beginning? Could we say Syn můj or omit můj?

Můj syn is the normal, neutral order: my son.
Syn můj is possible but sounds poetic, archaic, or strongly emphatic, like my son with special emotional emphasis (similar feel to English son of mine).

About omitting můj:

Czech often omits possessive adjectives when the owner is clear from context, especially with close family members, but it depends:

Syn ještě spí v pokoji.
Could be understood as My son is still sleeping in the room, but without context it might also mean The son is still sleeping… (whose son?).

If you want to be clear and neutral, Můj syn is the best choice here.

What is the difference between můj and svůj? Could we use svůj syn in this sentence?

Both are possessive, but:

můj = my (belongs to me)
svůj = one’s own, a special reflexive possessive that refers back to the subject of the sentence.

In this sentence, the subject is Můj syn itself (the son). He is not owning himself; I am the owner. So svůj syn would make no sense here.

Compare:

Můj syn ještě spí v pokoji.
Subject: my son
Owner: I (speaker)
můj is correct.
Můj syn miluje svou školu. – My son loves his (own) school.
- Subject: Můj syn
- Owner of the school: he (my son)
  Here we use svou (form of svůj) because the possessor is the subject.

So in your sentence, Můj syn is correct; Svůj syn would be wrong.

Why is there no word for the in syn, pokoji, and škole? How do you know when it means the and not a?

Czech has no articles (no equivalents of English a / an / the). Whether you translate a Czech noun as a or the depends entirely on context.

syn can be a son or the son
pokoji can be in a room or in the room
do školy can be to school or to the school

In your sentence, context makes it natural in English to say:

My son is still sleeping in the room and doesn’t want to go to school.

We assume we know which son and which room and which school, so English chooses the or a bare noun (school) even though Czech just uses the noun forms without any article.