Learn Hardcore Czech: Moje dcera nemá ráda počítačové hry, její oblíbená hra je ta, kterou hraje s kamarádkami v parku. - My daughter doesn't like computer games, her favourite game is the one she plays with her female friends in the park.

nemiluje is grammatically OK but sounds too strong and emotional (closer to “doesn’t love”), not natural for ordinary likes/dislikes like games, food, etc.
nelíbí se jí počítačové hry is possible and means “computer games are not pleasing to her”. It’s fine, but (ne)mít rád is the most common everyday way to talk about liking or not liking things, especially activities and objects.

So nemá ráda is the idiomatic, default way to say “doesn’t like” here.

Why is it ráda and not rád or rádi in nemá ráda?

The word rád/ráda/rádo/rádi/rády agrees in gender and number with the subject, not with the object.

Subject here: moje dcera (my daughter) → feminine singular → ráda.

Examples:

Můj syn nemá rád počítačové hry. (my son – masculine sg.)
Moje dcera nemá ráda počítačové hry. (my daughter – feminine sg.)
Moje děti nemají rády počítačové hry. (my children – feminine plural, or group of only girls)
Moji kamarádi nemají rádi počítačové hry. (friends – mixed group/men → rádi)

So:
dcera → ona → ráda.

What grammatical case is počítačové hry, and why is it plural?

počítačové hry is in the accusative plural.

Verb: (ne)mít rád koho/co? → “to like whom/what?” (direct object → accusative)
Noun: hra (a game), feminine:
- nominative sg: hra
- accusative sg: hru
- nominative pl: hry
- accusative pl: hry

In this sentence, we mean “computer games” in general, so Czech (like English) uses the plural:

nemá ráda co? → počítačové hry (acc. pl.)

Using počítačovou hru (singular) would sound like talking about one specific game.

Why is it moje dcera and not můj dcera? And what about má dcera?

The possessive můj (“my”) changes form according to the gender of the noun it modifies.

Masculine singular: můj
- můj syn (my son)
Feminine singular: moje or shorter má
- moje dcera / má dcera (my daughter)
Neuter singular: moje
- moje auto (my car)

Because dcera is a feminine noun, you must use moje (or má):

Moje dcera – neutral, everyday
Má dcera – a bit more formal/literary style, still correct

Můj dcera is grammatically wrong because můj is masculine.

Why is it její oblíbená hra and not svá oblíbená hra?

Czech has a special reflexive possessive svůj/svá/svoje, which refers back to the subject of the same clause.

In Její oblíbená hra je ta, kterou…, the grammatical subject of this clause is hra (game), not the daughter.

její oblíbená hra = her favourite game (possessor is “her”, i.e. the daughter mentioned earlier, but the subject of the verb je is hra)
If you said svá oblíbená hra, it would mean “the game’s own favourite game” (referring back to hra as the subject), which makes no sense.

So you must use její (her) to refer to another person (the daughter) and not the subject of this clause.

svůj would be used like this, where the subject is the possessor:

Dcera má svou oblíbenou hru. (The daughter has her own favourite game.)

What is the role of ta, kterou? Could I just say její oblíbená hra je hra, kterou…?

Yes, you could say:

Její oblíbená hra je hra, kterou hraje…

But ta, kterou… is more natural and less repetitive.

ta = “the one”, a demonstrative pronoun referring back to hra (feminine singular, nominative)
její oblíbená hra je ta = “Her favourite game is the one…”
kterou hraje… = “which she plays…”

So structurally:

Její oblíbená hra (subject)
je (verb “is”)
ta (predicate complement: “the one”)
kterou hraje s kamarádkami v parku (relative clause specifying ta hra)

Using hra, kterou… is also correct, just more repetitive. Using ta, kterou… sounds very natural.

Why is it kterou and not která in ta, kterou hraje s kamarádkami v parku?

The form of který/která/které/kterou… depends on the grammatical role of the pronoun in the relative clause.

Here:

Relative clause: (ona) hraje kterou? → “she plays which (game)?”
So kterou is the direct object of hraje → accusative feminine singular.

Compare:

Hra, kterou hraje. – The game which she plays.
- kterou = object (accusative)
Hra, která se jí líbí. – The game that she likes.
- která = subject of líbit se (nominative)

So která = subject (who/which)
kterou = direct object (whom/which).

Should it be hraje si instead of hraje when children are playing? What is the difference?

Both verbs exist in Czech but are used a bit differently:

hrát (without si) = to play something (a game, football, an instrument)
- hraje hru – she plays a game
- hraje fotbal – she plays football
hrát si = to play in the sense of children amusing themselves, often with toys or with other kids
- Děti si hrají v parku. – The children are playing in the park.
- Dcera si hraje s kamarádkami. – My daughter is playing with her friends.

In the given sentence:

hra, kterou hraje s kamarádkami v parku is fine and puts the focus on “playing that game”.
If you want to emphasise children’s free play, you might say:
- …hra, kterou si s kamarádkami v parku hraje.
  (possible, but stylistically a bit heavier)
- Or more naturally: …hra, kterou hraje s kamarádkami v parku, and then separately: S kamarádkami si hraje v parku.

So the original hraje is perfectly acceptable and idiomatic here.

What case is s kamarádkami, and why that ending?

The preposition s (“with”) requires the instrumental case.

Questions:

s kým? – with whom?
s čím? – with what?

Noun: kamarádka (female friend)

nominative sg: kamarádka
instrumental sg: s kamarádkou
instrumental pl: s kamarádkami

So s kamarádkami = “with (her) (girl)friends”.

Other variants:

s kamarády – with (male/mixed) friends (instrumental plural of kamarád)
s přáteli – with friends (somewhat more formal)

What case is v parku, and how is it different from do parku?

v parku uses the locative case after v when it means “in, inside” a place (location).

kde? – where?
- v parku – in the park (locative)
kam? – where to?
- do parku – to the park (genitive after do)

So:

hraje s kamarádkami v parku – she plays with her friends in the park (location).
jde do parku – she is going to the park (direction).

Is the comma between the two parts of the sentence necessary, and could I use ale there?

The sentence has two independent clauses:

Moje dcera nemá ráda počítačové hry,
její oblíbená hra je ta, kterou hraje s kamarádkami v parku.

In Czech, a comma is normally used to separate such clauses, even without a conjunction. It’s similar to using a semicolon or a comma in English.

You can add ale (“but”) to emphasise the contrast:

Moje dcera nemá ráda počítačové hry, ale její oblíbená hra je ta, kterou…

Both versions are correct:

With just a comma → neutral: two related statements.
With ale → explicit contrast: “She doesn’t like computer games, but (still) her favourite game is…”