La meva filla es posa trista quan la seva amiga no pot venir.

Catalan usually puts the definite article before a possessive plus noun:

• la meva filla = my daughter
• la seva amiga = her/his/their friend

This is very normal in Catalan. English does not do this, so it can feel strange at first.

A few basic examples:

• el meu pare = my father
• la nostra casa = our house
• els seus llibres = his/her/their books

So in this sentence, la meva filla is the standard Catalan way to say my daughter.

Es posa comes from posar-se, which often means to become, to get, or to turn when talking about a change of state.

So:

• es posa trista = becomes sad / gets sad

This is a very common Catalan structure:

• posar-se content/a = to become happy
• posar-se nerviós/nerviosa = to get nervous
• posar-se malalt/a = to get sick

Literally, posar means to put, but posar-se often has this idiomatic meaning of changing into a state.

The es is the reflexive pronoun that goes with posar-se.

In dictionary form, the verb is:

• posar = to put
• posar-se = to become / to get

In the 3rd person singular, that becomes:

• ell/ella es posa = he/she gets/becomes

So es posa trista is not literally puts herself sad in natural English, but grammatically it uses the reflexive form in Catalan.

Because trista agrees with filla, which is feminine singular.

• filla = daughter → feminine singular
• therefore the adjective must also be feminine singular: trista

Compare:

• El meu fill es posa trist. = My son gets sad.
• La meva filla es posa trista. = My daughter gets sad.

In Catalan, adjectives often change form to match gender and number.

Because amiga is the feminine form of amic.

• amic = male friend
• amiga = female friend

Since the sentence says la seva amiga, the friend is female.

Compare:

• el seu amic = his/her male friend
• la seva amiga = his/her female friend

Seva is a possessive meaning his, her, its, or sometimes even their, depending on context.

In this sentence, la seva amiga most naturally means her friend, referring to the daughter’s friend. But by itself, seva does not tell you the owner’s gender as clearly as English does.

Forms:

• el seu / la seva / els seus / les seves

These forms agree with the thing possessed, not with the possessor:

• la seva amiga = his/her friend
• el seu amic = his/her friend
• les seves amigues = his/her friends

So seva is feminine singular because amiga is feminine singular.

In Catalan, negation normally goes before the conjugated verb:

• no pot venir = cannot come

Here:

• pot = can / is able to
• venir = to come
• no pot venir = cannot come

If you said pot no venir, that would usually mean something more like she may not come or she might choose not to come, depending on context. So the meaning changes.

Because pot is a modal verb, like can in English.

Structure:

• poder + infinitive
• pot venir = can come
• pot menjar = can eat
• pot sortir = can leave

So venir stays in the infinitive because it depends on pot.

Yes, here quan means when.

In this sentence it introduces a time clause:

• quan la seva amiga no pot venir = when her friend can’t come

Depending on context, quan can sometimes sound close to whenever in English, especially if the sentence describes something habitual:

• La meva filla es posa trista quan la seva amiga no pot venir. = My daughter gets sad when her friend can’t come. = possibly whenever her friend can’t come

So the exact English translation can vary a little depending on context.

Because trista is a predicate adjective after the verb phrase es posa.

Catalan does not use an article there:

• es posa trista = gets sad
• està contenta = is happy
• sembla cansat = seems tired

You use the adjective directly, not la trista.

Yes, but the meaning is slightly different.

• està trista = she is sad
• es posa trista = she becomes sad / she gets sad

So:

• està trista describes a state
• es posa trista emphasizes the change into that state

In your sentence, es posa trista is a good choice because it suggests that the daughter becomes sad when the friend cannot come.

The structure is:

• La meva filla = subject
• es posa trista = verb phrase
• quan la seva amiga no pot venir = subordinate clause of time

So, very roughly:

[Subject] + [verb phrase] + [when-clause]

This is quite close to English:

• My daughter gets sad when her friend can’t come.

Catalan and English are similar here, which makes this sentence relatively beginner-friendly.

You would need to change agreement in several places:

• Les meves filles es posen tristes quan la seva amiga no pot venir.

Changes:

• La → Les
• meva → meves
• filla → filles
• es posa → es posen
• trista → tristes

Notice that la seva amiga could stay singular if both daughters share one female friend.

It is general, standard Catalan and would be understood everywhere Catalan is spoken.

Everything in it is very normal standard usage:

• la meva filla
• es posa trista
• quan
• la seva amiga
• no pot venir

So this is a good model sentence for learners.