Learn Hardcore Czech: Mému bratrovi se líbí dlouhé filmy, ale mně se líbí krátké seriály. - My brother likes long films, but I like short TV series.

English: My brother likes long films.
→ My brother = subject, films = object.
Czech: Dlouhé filmy se líbí mému bratrovi.
→ Dlouhé filmy (long films) = subject (NOMINATIVE)
→ mému bratrovi (to my brother) = indirect experiencer (DATIVE)

So „Mému bratrovi“ is in the dative case because the meaning is literally:
“Long films are pleasing to my brother.”

That’s why it isn’t „Můj bratr se líbí…“ (which would mean “my brother is liked…”).

What is the role of “se” in “se líbí”?

„Se“ is a reflexive pronoun, but with „líbit se“ it’s basically part of the verb. You should learn the verb as a whole: „líbit se někomu“ = “to be pleasing to someone / for someone to like something.”

Without „se“, „líbit“ is not used in this sense.
You can move „se“ around a bit because it’s a clitic (weak unstressed word), so both:
- „Mému bratrovi se líbí…“
- „Mému bratrovi líbí se…“ (less common, more emphatic)
are theoretically possible, but the normal way is like in the sentence: „Mému bratrovi se líbí…“.

Why is it “Mému bratrovi se líbí…” and not “Líbí se mému bratrovi…”?

Both orders are grammatically correct:

Mému bratrovi se líbí dlouhé filmy.
Líbí se mému bratrovi dlouhé filmy.

Czech word order is flexible. The difference is mainly emphasis:

„Mému bratrovi se líbí dlouhé filmy…“
starts with “to my brother” – it emphasizes whose taste we’re talking about.
„Líbí se mému bratrovi dlouhé filmy…“
starts with the verb, giving a bit more neutral or “announcing” feel: “What my brother likes is long films.”

In everyday speech, the version you have („Mému bratrovi se líbí…“) is very natural.

What’s the difference between “líbí se mi” and “mám rád”?

Both can translate to “I like”, but they’re not identical:

„líbí se mi“
- literally: “is pleasing to me”
- typical for first impressions, appearance, sensory things
- e.g. Líbí se mi ten film. = I like that film (it appeals to me).
„mám rád“ (masc speaker) / „mám ráda“ (fem speaker)
- literally: “I have [it] gladly”
- more about stable preferences, affection, fondness
- e.g. Mám rád dlouhé filmy. = I like long films (in general).

In your sentence, „líbí se“ is fine because we’re talking about what kind of things are pleasing to someone as a preference. You could also say:

Můj bratr má rád dlouhé filmy, ale já mám rád krátké seriály.

That’s also correct, just a slightly different style.

Why is it “mně” and not “mě” or “já”?

There are two forms of the 1st person singular dative/accusative pronoun:

mě – usually unstressed / weak form
mně – stressed form (used for emphasis or contrast)

In your sentence:

Mému bratrovi se líbí dlouhé filmy, ale mně se líbí krátké seriály.

„mně“ is strongly contrasted with „mému bratrovi“ using „ale“ (but), so the stressed form is used:

…ale mně se líbí… = “but *I (on the other hand) like…”*

Using „mě“ here would sound too weak and somewhat unnatural.

We don’t use „já“ here because the verb construction is „líbit se někomu“ (dative), not „já líbím…“. So the correct case is dative (mně), not nominative (já).

Why do the adjectives end in “-é”: “dlouhé filmy, krátké seriály”?

Adjectives have to agree with the nouns in:

gender
number
case

Both „filmy“ (films) and „seriály“ (series) are:

masculine inanimate
plural
accusative (they are the subject in form but syntactically behave like the nominative with „líbit se“ — for adjectives, it’s the same ending anyway)

For masculine inanimate plural in nominative/accusative, the adjective ending is -é:

dlouhé filmy – long films
krátké seriály – short series
nové stoly – new tables
staré domy – old houses

So “-é” is simply the correct agreement form here.

Why is it “filmy” and “seriály”, not “filmy se líbí mému bratrovi” in some other case like “filmů”?

„filmy“ and „seriály“ are in the nominative plural because they are the grammatical subject of the verb „líbit se“:

Dlouhé filmy se líbí mému bratrovi.
Long films are pleasing to my brother.

Subject (what is pleasing?) → filmy / seriály → nominative plural
Experiencer (to whom?) → mému bratrovi / mně → dative

„filmů“ would be genitive plural, used in different structures (e.g. hodně filmů – a lot of films, bez filmů – without films), not here.

How do I pronounce “mně”? It looks strange.

„mně“ is pronounced approximately like [mnye]:

m – as in man
n – as in no
ě – signals that the preceding consonant is palatalized (softened), so „ně“ sounds close to English “nye” (like in canyon “ny”).

So:

mně ≈ “m-nye” (said quickly together)

It’s one syllable in Czech, but English speakers often find it easier if they think “m-nye” at first.

Why is there a comma before “ale”?

In Czech, „ale“ = “but” is normally preceded by a comma when it connects two clauses:

Mému bratrovi se líbí dlouhé filmy, ale mně se líbí krátké seriály.

You have:

Mému bratrovi se líbí dlouhé filmy.
Mně se líbí krátké seriály.

These are two full clauses, so they are joined with a comma + ale. This is very similar to English:

My brother likes long films, but I like short series.

Can I say “Já mám rád krátké seriály” instead of “mně se líbí krátké seriály”?

Yes, you can. Both are correct, but they use different verb constructions:

Mně se líbí krátké seriály.
literally: Short series are pleasing to me.
– uses „líbit se někomu“ (dative).
Já mám rád krátké seriály. (male speaker)
Já mám ráda krátké seriály. (female speaker)
– uses „mít rád něco“ (accusative).

Stylistically:

„mám rád“ sounds a bit more straightforward and is very common for general likes/dislikes.
„líbí se mi“ often has a nuance of impression/appeal, but can also describe preferences, as in the sentence.

If you keep the original structure, a parallel version would be:

Můj bratr má rád dlouhé filmy, ale já mám rád krátké seriály.

Can I say “Dlouhé filmy se líbí mému bratrovi, ale krátké seriály se líbí mně”? Does it sound natural?

Yes, that sentence is grammatically correct and understandable:

Dlouhé filmy se líbí mému bratrovi, ale krátké seriály se líbí mně.

This word order:

puts “dlouhé filmy” and “krátké seriály” at the very beginning of each clause
emphasizes the things liked, more than who likes them.

Your original sentence:

Mému bratrovi se líbí dlouhé filmy, ale mně se líbí krátké seriály.

emphasizes the people (my brother vs. me). Both are fine; the original is more typical in everyday speech for talking about differing tastes.

Is “líbí” in the past, present, or future tense here?

„Líbí“ is present tense of „líbit se“:

líbí se – (it) is pleasing (now / generally)
líbilo se – (it) was pleasing (past)
bude se líbit – (it) will be pleasing (future)

However, in a sentence like yours, the present tense often expresses a general, timeless preference:

Mému bratrovi se líbí dlouhé filmy
= My brother likes long films (as a general fact, not only right now).

This is the same usage as in English: I like coffee (general present).