Antes de que lleguen mis padres, paso la mopa por la cocina para que todo esté limpio.

Use antes de que when it is followed by a conjugated verb:

• Antes de que lleguen mis padres = Before my parents arrive

Use antes de when it is followed by an infinitive or a noun:

• Antes de llegar mis padres ❌ not correct
• Antes de llegar mis padres sounds wrong because llegar would need a different structure
• Antes de que lleguen mis padres ✅
• Antes de llegar = Before arriving
• Antes de la cena = Before dinner

So in this sentence, because lleguen is a full verb form, you need que.

Because antes de que normally triggers the subjunctive.

Spanish uses the subjunctive after expressions like antes de que because the action has not happened yet from the point of view of the main clause. It is seen as pending, anticipated, or not presented as a completed fact.

So:

• Antes de que lleguen mis padres = Before my parents arrive

Not:

• Antes de que llegan mis padres ❌

This is a very common pattern:

• Te llamaré antes de que salgas.
• Hazlo antes de que sea tarde.

Because para que also requires the subjunctive.

Para que introduces a purpose clause: it explains the purpose of the action.

• paso la mopa por la cocina = I mop the kitchen / I run the mop over the kitchen floor
• para que todo esté limpio = so that everything is clean

After para que, Spanish uses the subjunctive because the result is something intended or desired, not simply stated as a fact.

Compare:

• Lo hago para que estés bien.
• Cierra la ventana para que no entre frío.

So esté is there because it follows para que.

Spanish often uses the present tense to talk about a habitual action, a general routine, or something the speaker normally does in that situation.

So:

• Antes de que lleguen mis padres, paso la mopa...

can mean something like:

• Before my parents arrive, I mop the kitchen
• I mop the kitchen before my parents arrive

It sounds like a regular or typical action.

If you wanted to refer to one future occasion more explicitly, you could say:

• Antes de que lleguen mis padres, pasaré la mopa por la cocina.

That would mean:

• Before my parents arrive, I’ll mop the kitchen.

Both are possible, but the present tense is very natural for routines or planned actions.

Pasar la mopa is a common Spain Spanish expression meaning:

• to mop
• to run a mop over the floor
• sometimes more specifically to go over the floor with a mop

Literally, pasar means to pass or to move something over a surface, so pasar la mopa is to pass the mop over the floor.

In Spain, this is very natural. Depending on context, people might also say:

• fregar el suelo = to mop/scrub the floor
• pasar la fregona = to mop with a wet mop
• pasar la mopa = often to go over it with a mop, sometimes a dry mop depending on context

So this sentence sounds very Spain Spanish.

With pasar la mopa, Spanish often uses por to express moving the mop over/through/across the area.

So:

• paso la mopa por la cocina = I run the mop over the kitchen floor / around the kitchen

Here por suggests the action moving across that space.

If you say:

• en la cocina

that just means in the kitchen, focusing more on location than on the movement of the mop across the surface.

Both can make sense in some contexts, but with pasar + object, por is especially natural:

• pasar la aspiradora por el salón
• pasar un trapo por la mesa

Here todo means everything, not all people/things in a countable plural sense.

So:

• todo = everything
• todos = all / everyone / all of them

Because todo is grammatically treated as singular, the verb is singular:

• todo esté ✅

And the adjective is singular too:

• limpio ✅

So:

• para que todo esté limpio = so that everything is clean

Compare:

• Quiero que todo esté listo. = I want everything to be ready.
• Quiero que todos estén listos. = I want everyone to be ready.

Because todo here is grammatically singular and takes the default masculine singular form.

In Spanish, when todo means everything, adjectives usually appear in masculine singular:

• todo está bien
• todo está listo
• todo esté limpio

This does not mean the speaker is talking about something specifically masculine. It is just the standard grammatical form used with todo meaning everything.

Yes, absolutely.

Both orders are correct:

• Antes de que lleguen mis padres
• Antes de que mis padres lleguen

Spanish word order is fairly flexible here.

The version in your sentence puts slightly more focus on the verb first within the subordinate clause, but both are natural. Many learners will probably hear or say:

• Antes de que mis padres lleguen, paso la mopa...

That may feel a little more straightforward because it follows the subject-verb order English speakers expect.

Because the sentence begins with a subordinate clause:

• Antes de que lleguen mis padres, ...

When a time clause or other subordinate clause comes before the main clause, Spanish normally separates it with a comma.

So:

• Antes de que lleguen mis padres, paso la mopa...

If the main clause comes first, the comma is often not needed:

• Paso la mopa por la cocina antes de que lleguen mis padres.

That is also a very natural way to say it.

No, esté limpio is the natural choice here.

Spanish usually uses estar + adjective for a resulting state or condition like clean, open, ready, closed, etc.

So:

• todo esté limpio = so that everything is clean

Using ser here would sound unnatural because ser limpio usually refers more to a general characteristic, like to be a clean person/thing by nature or habit, not the temporary result of cleaning.

Compare:

• La cocina está limpia. = The kitchen is clean.
• Mi hermano es muy limpio. = My brother is very clean/tidy.

Yes, it sounds very natural in Spain, especially because of paso la mopa.

A speaker from another Spanish-speaking region might understand it perfectly, but they might choose a different expression, such as:

• paso el trapeador
• trapear
• paso la fregona
• friego el piso/suelo

But in Spain, mopa and cocina in this sentence sound very normal.

No. In this meaning, you need antes de que.

• antes de que lleguen mis padres ✅
• antes que lleguen mis padres ❌

Spanish uses the full expression antes de que before a clause with a conjugated verb.

This is just a fixed structure you should learn as a unit:

• antes de que + subjunctive

Yes, very much so. It contains two very common subjunctive triggers:

• antes de que + subjunctive
• para que + subjunctive

So the sentence is a great model:

• Antes de que lleguen mis padres → lleguen is subjunctive
• para que todo esté limpio → esté is subjunctive

This is a useful pattern to remember because it appears constantly in everyday Spanish.