Si el tren té retard, truca'm abans de la reunió.

Si means if. It introduces a condition:

• Si el tren té retard = If the train is delayed / if the train is late

So the whole sentence is a conditional: if X happens, do Y.

Be careful not to confuse si with sí:

• si = if
• sí = yes

The accent makes them different words.

In Catalan, a singular countable noun usually needs an article or another determiner.

So:

• el tren = the train

A bare singular noun like tren on its own would usually sound incomplete here.

This is similar to English, where you would normally say the train, a train, my train, etc., not just train.

That is just a normal Catalan way to express the idea.

• tenir retard = to be delayed / to be running late

So el tren té retard literally looks like the train has delay, but it naturally means the train is delayed.

Catalan often uses structures that do not match English word-for-word. You may also hear other expressions, such as:

• el tren va amb retard
• el tren arriba amb retard

All of these can express that the train is late or delayed.

The accent in té is important.

• té = he/she/it has
• te without an accent is a different word

Here, té is the 3rd person singular of tenir (to have):

• jo tinc
• tu tens
• ell/ella té

So el tren té retard literally means the train has delay.

Because Catalan, like English, often uses the present tense after if when talking about a future possibility.

• Si el tren té retard, truca'm...

This does not mean only if the train is delayed right now. It can also mean if the train ends up being delayed in the relevant future situation.

A very important point: after si meaning if, Catalan normally does not use the future tense the way English learners might expect. So a form like si el tren tindrà retard would normally be wrong here.

This is similar to English:

• If the train is late, call me not
• If the train will be late, call me

Because truca'm is a command.

• truca = call! (addressed to tu)
• 'm = me

So:

• truca'm = call me

By contrast, em truca means he/she calls me or is calling me, which is not a command.

So the sentence is telling someone what to do if the condition happens.

In Catalan, with an affirmative imperative (a positive command), object pronouns are attached to the end of the verb.

So:

• truca + em → truca'm

This is normal Catalan word order for commands:

• digues-me = tell me
• porta'l = bring it
• espera'ns = wait for us

But in many other verb forms, the pronoun goes before the verb:

• em truca = he/she calls me
• em trucaràs = you will call me

So the position of the pronoun changes depending on the verb form.

The apostrophe shows that the pronoun em has been reduced when attached after a verb ending in a vowel.

• truca + em becomes truca'm

This is done for normal spelling and pronunciation reasons.

So the apostrophe here is not optional; it is the correct written form.

Because Catalan often leaves out subject pronouns when they are already clear from the verb form.

• truca already means you call / call! addressed to tu

So tu is unnecessary unless you want emphasis or contrast.

Catalan does this much more often than English. English usually needs the subject pronoun, but Catalan often does not.

Because abans normally takes de before a noun.

• abans de la reunió = before the meeting

So the pattern is:

• abans de + noun
• abans de + infinitive

Examples:

• abans de classe = before class
• abans de sortir = before leaving

You can use abans on its own when no noun or verb follows:

• Truca'm abans. = Call me beforehand / earlier.

La reunió means the meeting.

The article is used because this is a specific meeting that both speaker and listener know about.

• la reunió = the meeting

In context, it is not just any meeting; it is a particular one.

Also, reunió is a feminine noun, which is why it takes la, not el.

You could translate it literally that way to understand the structure, but it is not natural English.

A more natural English translation is:

• If the train is delayed, call me before the meeting.
• If the train is late, call me before the meeting.

This is a good example of why you should learn the Catalan expression as a whole, rather than translating word by word.