Ahir vaig aprovar un examen, però la meva amiga el va suspendre.

This is a very common Catalan past tense, especially in everyday language: the periphrastic past.

It is formed with:

• a present-tense form of anar (vaig, vas, va, vam, vau, van)
• plus an infinitive

So:

• vaig aprovar = I passed
• va suspendre = she failed

In this sentence:

• vaig is used because the subject is I
• va is used because the subject is la meva amiga = my friend

So the pattern is:

• jo vaig + infinitive
• tu vas + infinitive
• ell/ella va + infinitive

Because they are different forms of the auxiliary part of the periphrastic past.

Here are the relevant forms:

• jo vaig
• tu vas
• ell/ella va
• nosaltres vam
• vosaltres vau
• ells/elles van

So:

• vaig aprovar = I passed
• la meva amiga va suspendre = my friend failed

Even though vaig comes from the verb anar, in this structure it does not mean I go. It is just part of the past tense.

Ahir means yesterday. It tells you when the action happened.

It is placed at the beginning here:

• Ahir vaig aprovar un examen...

That is very natural, but Catalan word order is flexible. You could also say:

• Vaig aprovar un examen ahir...

Putting ahir first gives it a little more prominence, similar to English Yesterday, I passed an exam...

Because examen is masculine in Catalan, so it takes the masculine singular article un.

So:

• un examen = an exam

This is worth remembering because noun gender does not always match what an English speaker might expect. You usually need to learn the article together with the noun:

• un examen
• una amiga

In Catalan, possessives are often used together with the definite article.

So:

• la meva amiga = my friend
• literally something like the my friend

This is normal Catalan grammar. English usually does not use the with possessives, but Catalan often does.

Some more examples:

• el meu germà = my brother
• la nostra casa = our house

So la meva amiga is the expected form here.

El is a direct object pronoun. It refers back to un examen.

So instead of repeating the noun, Catalan uses the pronoun:

• Ahir vaig aprovar un examen, però la meva amiga el va suspendre.
• Yesterday I passed an exam, but my friend failed it.

Here:

• el = it
• it is masculine singular because examen is masculine singular

This is very common in Catalan and Romance languages: once the object has already been mentioned, you often replace it with a pronoun.

In Catalan, unstressed object pronouns normally go before the conjugated verb.

So:

• el va suspendre = she failed it
• not va suspendre el in this structure

The order is:

• pronoun + auxiliary + infinitive

Other examples:

• la vaig veure = I saw her
• els vam comprar = we bought them

So el va suspendre is the normal placement.

Yes, absolutely.

Both are grammatical:

• la meva amiga el va suspendre
• la meva amiga va suspendre l'examen

The version with el is more natural when the exam has already been mentioned and you do not want to repeat the noun.

So:

• first mention: un examen
• second mention: el

That works much like English an exam ... it, except Catalan places the pronoun before the verb.

Yes. In the context of school or exams, aprovar means to pass.

That can be confusing for English speakers because it resembles approve. In Catalan:

• aprovar un examen = to pass an exam
• aprovar una assignatura = to pass a subject/course

Depending on context, aprovar can also mean approve, but in this sentence with un examen, the meaning is clearly pass.

Yes. In school/exam contexts, suspendre means to fail.

So:

• suspendre un examen = to fail an exam

This is another common false friend for English speakers, because it looks like English suspend. In education, though, the Catalan meaning is very often fail.

So in the sentence:

• la meva amiga el va suspendre means
• my friend failed it

The accent in però is part of the normal spelling of the word meaning but.

It helps mark pronunciation and distinguish the vowel quality. In Catalan, accents are very important and are not optional decoration.

So you should learn the word as:

• però = but

It is a very common conjunction.

Because però introduces a contrast between the two parts of the sentence:

• I passed an exam
• but my friend failed it

Using a comma before però is standard punctuation here, just like using a comma before but in many English sentences with two full clauses.

Yes. Catalan word order is fairly flexible, especially with time expressions.

For example:

• La meva amiga el va suspendre, però ahir vaig aprovar un examen.
• Vaig aprovar un examen ahir, però la meva amiga el va suspendre.

However, the original sentence is very natural because:

• ahir sets the time right away
• then the sentence contrasts I passed with my friend failed

So the original order is a good, idiomatic choice.

Yes. Amiga is feminine, so it refers to a female friend.

That matches:

• la meva amiga = my female friend

If the friend were male, you would say:

• el meu amic = my male friend

Then the sentence would become:

• Ahir vaig aprovar un examen, però el meu amic el va suspendre.

So both the article and the possessive change with gender:

• la meva amiga
• el meu amic