Learn Hardcore Czech: Moje sestra říká, že se jí nelíbí, když se díváme na hlasitý film. - My sister says that she doesn’t like it when we watch a loud film.

líbit se + DAT literally means “to be pleasing to someone”.
- líbí se jí = “it is pleasing to her” → “she likes it”
- nelíbí se jí = “it is not pleasing to her” → “she doesn’t like it”
jí is the dative of ona (to her).
se is a reflexive particle that belongs to the verb líbit (se); you always use it in this construction.

You could say Ona to nemá ráda (she doesn’t like it), but:

(ne)líbit se is very common and often sounds more neutral/natural.
nemít rád is a bit more about attitude/affection, e.g. Nemám rád horory (I don’t like horror movies).

Here the pattern nelíbí se jí, když… (she doesn’t like it when…) is idiomatic and very natural.

What is the subject in the part „se jí nelíbí, když se díváme na hlasitý film“?

The subject is actually the clause „když se díváme na hlasitý film“ (when we watch a loud movie).

So structurally:

(To) se jí nelíbí,
když se díváme na hlasitý film.

You can imagine an implicit To (that) as the subject:

To se jí nelíbí = She doesn’t like that.

The jí (to her) is not the subject; it’s an indirect object in dative. The verb (ne)líbit se agrees with the thing that is (not) pleasing – here, the whole “when we watch a loud movie” situation.

Why is there a „se“ after „říká, že“ and another „se“ in „díváme se“? Are they the same?

They are two different uses of se:

že se jí nelíbí
- Here se belongs to the verb líbit se.
- It’s part of the fixed construction (něco) se někomu líbí (something is pleasing to someone).
- You always use se with líbit in this sense.
když se díváme na hlasitý film
- Here se belongs to the verb dívat se (to look / to watch).
- dívat se na něco = to watch something.
- Again, se is part of the standard verb phrase.

So you just happen to have two different reflexive verbs in one sentence:

líbit se
dívat se (na něco)

Could I leave out any of the „se“ or „jí“ and still be correct?

No, in this sentence none of them can be omitted:

se jí nelíbí
- If you drop se, líbí jí is ungrammatical in this meaning.
- If you drop jí, (ne)líbí se would mean “it is (not) pleasing” in general, without saying to whom.
když se díváme na hlasitý film
- The standard verb is dívat se.
- dívat na film without se is non‑standard/wrong in this sense.

So in this sentence, se and jí are all mandatory parts of the grammar.

Why is it „Moje sestra říká, že…“ and not just „Moje sestra se jí nelíbí, když…“?

You need a verb that introduces reported speech:

Moje sestra říká, že… = My sister says that…

se jí nelíbí, když… is a complete clause meaning “she doesn’t like it when…”, but it doesn’t by itself express “she says that”.

Without říká, you’d be saying:

Moje sestra se jí nelíbí, když…
which sounds like “My sister is not liked by her when…” — and is also structurally wrong/confusing in Czech.

So:

Moje sestra říká, že se jí nelíbí, když…
literally: My sister says that it is not pleasing to her when…

Why do we use „když“ here and not „kdy“?

když is a conjunction meaning “when” in the sense of:
- whenever / at the time that / if (whenever this happens).
kdy is usually an interrogative adverb meaning “when?” in questions:
- Kdy přijdeš? – When will you come?

In this sentence:

…když se díváme na hlasitý film = when(ever) we watch a loud movie.

You’re not asking a question, so you need když, not kdy.

What is the difference between „dívat se na film“ and „sledovat film“?

Both can mean “to watch a film”, but:

dívat se na film
- Very common, neutral expression.
- Literally “to look at a film”.
- Used for casual watching: TV, movies, YouTube, etc.
sledovat film
- Literally “to follow a film”.
- Can imply following the plot more attentively.
- Often used for following a series, a program, events: sledovat seriál / zprávy / zápas.

In your sentence, když se díváme na hlasitý film is perfectly natural and typical for everyday speech.

Why is it „na hlasitý film“ and not „hlasný film“ or just „hlasité filmy“?

Several points here:

na film
- With dívat se, you normally say dívat se na něco.
- So dívat se na film = to watch a movie.
hlasný vs hlasitý
- Both relate to loudness, but hlasitý is the common choice for a loud sound/noise/film/music.
- hlasný is less usual here and can feel a bit bookish or slightly awkward for a film.
- So hlasný film is possible but hlasitý film sounds more natural.
hlasitý film (singular) vs hlasitě (adverb)
- You could also say když se díváme na film, který je hlasitý or když se díváme na film příliš hlasitě (too loudly – focusing on volume setting).
- The original just compresses this into hlasitý film, which is idiomatic.

So na hlasitý film is “at a loud movie” in the sense of watch a movie that is loud.

Why is it „Moje sestra“ and not „Má sestra“?

Both Moje sestra and Má sestra are grammatically correct and mean “my sister”. The difference is mainly style and emphasis:

Moje sestra
- Neutral, very common in speech.
- Slightly more explicit; often used in everyday conversation.
Má sestra
- A bit shorter, often feels slightly more formal, literary, or stylistic.
- Still perfectly normal in modern Czech, just a bit “tighter”.

In your sentence, Moje sestra říká… sounds completely natural and colloquial. You could say Má sestra říká… as well; it’s just a stylistic choice.

Why is there a comma before „že“ and another before „když“?

In Czech, you usually separate subordinate clauses with commas.

Moje sestra říká, že…
- že se jí nelíbí, když se díváme na hlasitý film.

Structure:

Main clause: Moje sestra říká
Subordinate clause introduced by že:
- že se jí nelíbí, když se díváme na hlasitý film
Inside that, another subordinate clause introduced by když:
- když se díváme na hlasitý film

Each subordinate clause boundary is marked by a comma:

before že
before když

Why is „díváme se“ in the 1st person plural (we) and not something like an infinitive “when watching”?

Czech often uses a full finite clause after když:

když se díváme na hlasitý film
literally: “when we watch a loud movie”.

English frequently uses a non‑finite form:

“when watching a loud movie”.

In Czech grammar:

když + [finite verb] is the normal pattern.
The subject my (we) is understood from the verb ending:
- díváme (se) = we watch (1st person plural).

Using an infinitive like “když dívat se na film” would be ungrammatical.

Is the verb „říká“ in any special aspect here? Could it be „řekla“ instead?

Yes, aspect and tense matter:

říká = 3rd person singular, present tense, imperfective
→ “My sister says…” (general / habitual / current statement).

If you say:

Moje sestra řekla, že se jí nelíbí, když se díváme na hlasitý film.
- řekla = past tense (perfective říct)
- This means: “My sister said that she doesn’t like it when we watch a loud movie.” (a specific act of saying in the past).

Both are correct; they just describe different situations:

říká – what she (generally) says.
řekla – what she said on a particular occasion.