Learn Hardcore Spanish (Spain): Cuando el equipo visitante pierde, mi suegra siempre dice que lo importante es participar. - When the visiting team loses, my mother-in-law always says that the important thing is to take part.

When cuando introduces something that happens regularly / every time, you use the present indicative:
- Cuando el equipo visitante pierde, mi suegra siempre dice…
  = Every time this happens, she says that.
When cuando refers to a specific future action, you normally use the present subjunctive, not the future:
- Cuando el equipo visitante pierda, me voy a enfadar.
  = When the visiting team loses (in that future match), I’m going to get angry.

Using perderá after cuando here would sound wrong. Spanish almost never uses the simple future right after cuando for time clauses; it uses present (indicative or subjunctive) instead, depending on whether the action is seen as habitual/real (indicative) or future/uncertain (subjunctive).

What exactly does equipo visitante mean? Is there a standard phrase for the home team?

Equipo visitante literally means visiting team – the team that is playing away from home.

The usual pair is:

el equipo local – the home team
el equipo visitante – the visiting/away team

You might also hear:

el equipo de casa – the home team (more colloquial)
el equipo de fuera – the team from outside / the away team (colloquial)

In sports reporting in Spain, equipo local and equipo visitante are the standard, neutral terms.

Why is equipo singular with pierde in Spanish, when in English we often say “the team lose” (plural) in British English?

In Spanish, collective nouns like equipo are grammatically singular, so the verb agrees in the singular:

el equipo pierde – the team loses
el equipo gana – the team wins

You cannot say el equipo pierden; that’s incorrect in standard Spanish.

English has more flexibility (especially British English), where you can treat words like team, government, family as singular or plural depending on whether you think of them as a unit or as people. Spanish does not do this; it keeps the grammar strictly singular:

el equipo está cansado – the team is tired
la familia ha llegado – the family has arrived

What does mi suegra mean exactly, and what are the related family terms?

Mi suegra means my mother-in-law.

Related forms:

el suegro – father-in-law
la suegra – mother-in-law
los suegros – parents-in-law (both together)

Other in-law vocabulary, for context:

el yerno – son-in-law
la nuera – daughter-in-law
el cuñado – brother-in-law
la cuñada – sister-in-law

So in the sentence, it’s specifically my mother-in-law who always says that phrase.

What is the function of lo in lo importante es participar?

Here lo is the neuter definite article, and its job is to turn an adjective into an abstract noun – “the important thing”.

importante – important (adjective)
lo importante – that which is important / the important thing

So:

lo importante es participar ≈ “The important thing is to take part / participate.”

This neuter lo + adjective structure is very common:

lo bueno – the good thing
lo malo – the bad thing
lo interesante – the interesting part / what’s interesting

It does not mean the same as el or la. You use lo when you are talking about an idea or quality in general, not a specific masculine or feminine object.

Can the word order be changed? For example, can I say Mi suegra siempre dice que lo importante es participar cuando el equipo visitante pierde?

Yes, you can move the cuando clause without changing the meaning:

All of these are natural:

Cuando el equipo visitante pierde, mi suegra siempre dice que lo importante es participar.
Mi suegra siempre dice que lo importante es participar cuando el equipo visitante pierde.
Mi suegra, cuando el equipo visitante pierde, siempre dice que lo importante es participar. (with commas, more spoken style)

You can also move siempre:

Mi suegra siempre dice… (most common)
Mi suegra dice siempre… (also correct; sometimes slightly more emphasis on says rather than always)

The basic rules:

Time clauses with cuando are flexible in position.
Adverbs like siempre are also quite flexible, but the most neutral place is before the verb: siempre dice.

Could I say Cuando pierda el equipo visitante instead of Cuando el equipo visitante pierde?

You could, but it would change the meaning.

Cuando el equipo visitante pierde… (present indicative)
- Habitual: Whenever the visiting team loses (in general, every time this happens)…
Cuando pierda el equipo visitante… (present subjunctive)
- Future / uncertain: When the visiting team loses (in that future match or eventual situation)…

So:

In your original sentence, we are describing a repeated habit, so pierde (indicative) is the natural choice.
Cuando pierda… would sound like you are talking about a specific future game or situation, not a general habit.

Context decides whether cuando + indicative or cuando + subjunctive is appropriate.

Why is participar used as an infinitive here instead of a noun like la participación?

Spanish very often uses the infinitive as a noun, especially after ser to talk about general actions or activities:

Lo importante es participar. – The important thing is to participate / participating.
Lo mejor es descansar. – The best thing is to rest.
Mi hobby es leer. – My hobby is reading.

You could say la participación es lo importante, but:

It sounds more abstract and less like a natural proverb.
The fixed, idiomatic expression is lo importante es participar.

Also, participarse does not exist with this meaning; participar is not reflexive here.

Is lo importante es participar a common expression in Spanish? Does it have any cultural connotation?

Yes, lo importante es participar is a very well-known phrase in Spanish, especially in the context of sports and competitions.

It is used to express the idea that taking part matters more than winning.
It’s often linked (loosely) to the Olympic spirit attributed to Pierre de Coubertin (although the exact wording varies across languages).

In everyday speech, it can be:

Sincere: to comfort someone who lost or didn’t win.
Ironic: said with a joking tone after losing badly, as if to pretend that winning doesn’t matter.

In your sentence, a typical reading is that the mother-in-law says it only when the visiting team loses, possibly with a bit of irony or to console herself or others.

Why is there a comma after pierde, but no comma before que in dice que lo importante es participar?

The comma after pierde separates the when-clause (Cuando el equipo visitante pierde) from the main clause (mi suegra siempre dice…).
- Spanish normally uses a comma when a dependent clause comes before the main clause.
There is no comma before que in dice que… because que introduces a direct object clause (what she says):
- mi suegra dice algo → mi suegra dice que lo importante es participar

You generally do not put a comma between the verb decir, pensar, creer, etc. and their que-clause in modern Spanish punctuation.