Learn Hardcore Czech: Moje sestra občas poslouchá rádio v kuchyni. - My sister sometimes listens to the radio in the kitchen.

You can sometimes drop the possessive in very clear contexts (e.g. talking about mom/dad in the family), but with sestra it’s most natural to keep moje if you mean my sister, not just the sister in general.

Why moje and not můj? Aren’t they both “my”?

Yes, both mean my, but they agree with the gender and number of the noun:

můj – masculine animate singular (e.g. můj bratr – my brother)
moje – feminine singular and also neuter plural in basic (nominative) form

Since sestra is feminine, you need moje sestra, not můj sestra.

What’s the difference between občas and sometimes / often in English?

občas means sometimes, occasionally. It implies it doesn’t happen regularly or frequently.

Some rough equivalents:

občas – sometimes / occasionally
někdy – sometimes (more neutral; can also mean “ever” in some questions)
často – often / frequently
zřídka / málokdy – rarely / seldom

So Moje sestra občas poslouchá rádio = My sister sometimes listens to the radio.

Could I put občas somewhere else in the sentence?

Yes. Word order in Czech is flexible. All of these are possible and natural, with slight differences in emphasis:

Moje sestra občas poslouchá rádio v kuchyni. (neutral)
Moje sestra poslouchá občas rádio v kuchyni. (slight emphasis on “listens occasionally”)
Občas moje sestra poslouchá rádio v kuchyni. (emphasis on sometimes it happens)
Moje sestra poslouchá rádio občas v kuchyni. (more contrastive: as opposed to other places)

For a beginner, keeping občas early in the sentence (after the subject) is a safe default.

Why is it poslouchá and not something like a continuous form “is listening”?

Czech doesn’t have a special present continuous form like English (is listening). The present tense covers both:

Moje sestra poslouchá rádio.
– My sister listens to the radio.
– My sister is listening to the radio.

The exact meaning (habitual vs. right now) comes from context or extra words like teď (now), každý den (every day), etc.

What’s the difference between poslouchat and slyšet?

poslouchat = to listen (actively)
slyšet = to hear (perceive sound)

So:

poslouchám rádio – I’m listening to the radio (by choice)
slyším rádio – I can hear the radio (it’s audible; maybe in the background)

In your sentence, poslouchá is correct because the sister is listening on purpose.

Why does rádio look the same in the sentence as in the dictionary? Isn’t it supposed to change case?

rádio is a neuter noun ending in -o. In many cases, its nominative and accusative singular forms are identical:

Nominative (dictionary form): rádio – “a radio” (subject)
Accusative: rádio – “radio” (direct object)

In the sentence, rádio is a direct object of poslouchá, so it’s in accusative, but it just happens to look the same as nominative.

Why is it v kuchyni and not v kuchyně?

The preposition v (in) usually goes with the locative case when it means “in/inside” a place.

The noun kuchyně (kitchen) declines like this (singular, main forms):

Nominative: kuchyně (kitchen – subject)
Genitive: kuchyně
Dative: kuchyni
Accusative: kuchyni
Locative: kuchyni
Instrumental: kuchyní

After v meaning “in”, we use locative: v kuchyni = in the kitchen.

So v kuchyně is wrong; kuchyně is nominative, and you need locative: kuchyni.

How do I know kuchyni is locative and not accusative, since they look the same?

You can’t tell just from the form kuchyni; you need to look at the preposition and function:

With v meaning “in” (location), we expect locative → v kuchyni
If there were a verb that takes a direct object (accusative) without a preposition, e.g. Mám kuchyni (I have a kitchen), then kuchyni there is accusative.

So form-wise they’re identical; context and prepositions tell you which case it is.

Is there any article like “the” in v kuchyni? Does it mean in a kitchen or in the kitchen?

Czech has no articles (no a, an, the). v kuchyni can mean:

in a kitchen
in the kitchen

Which one you choose in English depends on context. Often, with a home context, English uses the:

Moje sestra občas poslouchá rádio v kuchyni.
→ My sister sometimes listens to the radio in the kitchen.

Can rádio mean both the physical device and radio broadcasting, like in English?

Yes, context decides:

poslouchat rádio – usually means “listen to radio programmes / radio broadcasting.”
koupil jsem nové rádio – I bought a new radio (device).

So your sentence is normally understood as listening to radio programmes, not literally listening to the box.

Could I say the same thing in a more colloquial way?

A few natural everyday variants:

Moje ségra občas poslouchá rádio v kuchyni.
– ségra is a colloquial word for sestra (sis).
Moje sestra si občas pouští rádio v kuchyni.
– pouští si rádio = “puts the radio on / plays the radio for herself.”

Your original sentence is perfectly standard and neutral.