Pase lo que pase, mi abuela quiere preparar flan cuando viene toda la familia.

Because this expression uses the present subjunctive, not the normal present indicative.

• pasa = it happens
• pase = whatever may happen / no matter what happens

In Spanish, the subjunctive is often used after words like lo que when the meaning is indefinite, open-ended, or concessive. Here, Pase lo que pase means no matter what happens, so Spanish uses the subjunctive.

This is a very common fixed pattern:

• Haga lo que haga = no matter what he/she does
• Diga lo que diga = no matter what he/she says
• Vaya donde vaya = wherever he/she goes

Very literally, it is something like:

May happen what may happen

That sounds unnatural in English, so the real meaning is:

• No matter what happens
• Whatever happens

The structure is idiomatic in Spanish, so it is best learned as a chunk: Pase lo que pase.

The repetition is part of the concessive pattern.

Structure:

• verb in subjunctive + lo que + same verb in subjunctive

So:

• Pase lo que pase
• Diga lo que diga
• Sea como sea

This repetition creates the meaning regardless of what X is/does/happens. It is not random repetition; it is a standard Spanish pattern.

In lo que, the word lo does not mean it here. It helps create a neuter expression meaning what / whatever that which.

So:

• lo que = what / whatever

In Pase lo que pase, lo que introduces the unknown or unspecified thing that may happen: whatever happens.

This lo is very common in Spanish:

• No entiendo lo que dices = I don’t understand what you are saying
• Haz lo que quieras = Do whatever you want

Because the subject of both verbs is the same: mi abuela.

• mi abuela quiere preparar flan = my grandmother wants to make flan

When one person wants to do something themselves, Spanish usually uses:

• querer + infinitive

Examples:

• Quiero comer
• Mi abuela quiere preparar flan

You would use quiere que prepare only if the subject changes:

• Mi abuela quiere que yo prepare flan = My grandmother wants me to make flan

In Spanish, after cuando referring to a habitual or general situation, the present tense is normal.

Here the idea is:

• whenever the whole family comes
• when the whole family comes over

So viene works well because it describes something that happens regularly.

Spanish often uses the present where English may also use the present:

• Cuando viene Juan, cenamos tarde
• Cuando hace calor, abrimos las ventanas

If you were talking about a future event that has not happened yet, Spanish often uses the present subjunctive:

• Cuando venga toda la familia, mi abuela preparará flan

So:

• cuando viene = whenever / when she comes, as a repeated or typical event
• cuando venga = when she comes, in the future

Because la familia is grammatically singular in Spanish.

Even though a family contains several people, the noun itself is singular:

• la familia viene
• la gente dice
• el grupo llega

So toda la familia viene is correct because the subject is la familia, not the individual family members.

If you changed the subject to the people themselves, then you would use plural:

• Vienen todos los miembros de la familia
• Vienen todos

Yes, but it changes the nuance.

• cuando viene toda la familia suggests a repeated, usual, or characteristic situation: whenever the whole family comes
• cuando venga toda la familia points more to a future or not-yet-realised event: when the whole family comes

So both are grammatical, but they do not mean exactly the same thing.

Because Spanish often omits the article when talking about food in a general sense, especially after verbs like preparar, comer, hacer, or servir.

So:

• preparar flan = to make flan
• hacer paella = to make paella
• comer pizza = to eat pizza

If you add an article, it usually sounds more specific:

• preparar el flan = prepare the flan, a particular flan already mentioned or understood
• preparar un flan = make a flan, one flan

Here preparar flan sounds natural as a general dish she likes to make.

Literally, quiere means wants to. But in context, it can suggest a very typical habit or preference.

So the sentence can imply:

• she always wants to make flan
• she insists on making flan
• she likes to make flan whenever the whole family comes

It does not directly say she always makes it, but it strongly suggests that this is her usual intention or preference.

If you wanted to state it more directly as a habit, you could say:

• mi abuela siempre prepara flan cuando viene toda la familia

Because Pase lo que pase is an introductory concessive expression.

It sets the scene before the main clause:

• Pase lo que pase, mi abuela quiere preparar flan...

In writing, Spanish normally separates this kind of introductory phrase with a comma, just as English does with:

• Whatever happens, my grandmother wants to make flan.

Yes. It is very common and very natural.

Spanish speakers use it to mean:

• whatever happens
• no matter what
• come what may

It can be used seriously or dramatically:

• Pase lo que pase, te ayudaré
• Pase lo que pase, seguimos adelante

So it is a very useful expression to learn as a complete chunk.

Yes. Some natural alternatives are:

• toda la familia
• la familia entera
• todos en la familia (slightly different emphasis)
• todos los de la familia (more colloquial)

In this sentence, toda la familia is the most neutral and straightforward option.

It combines two common structures:

1. A concessive expression:

   • Pase lo que pase = no matter what happens

2. A main clause with a time clause:

   • mi abuela quiere preparar flan cuando viene toda la familia

So the full idea is:

• No matter what happens, my grandmother wants to make flan whenever the whole family comes.

This is a very natural Spanish way to combine emphasis plus a habitual family situation.