La crèche ferme plus tôt le vendredi, alors il faut que les parents arrivent avant six heures du soir.

Here, la crèche means a daycare center or nursery for young children.

A common point of confusion is that crèche can also mean a nativity scene in another context. But in this sentence, because it talks about parents arriving before a certain time, it clearly means a childcare place.

La crèche ferme means the daycare closes.

In French, fermer can be used this way without an object, just like to close in English:

• Le magasin ferme à 8 heures.
• The shop closes at 8.

If you said la crèche est fermée, that would mean the daycare is closed, which describes its state, not the action of closing earlier than usual.

So:

• ferme = closes
• est fermée = is closed

Plus tôt means earlier.

So:

• La crèche ferme plus tôt le vendredi = The daycare closes earlier on Fridays

It does not mean more early in English, even though that is the literal structure. It is just the normal French way to say earlier.

Le vendredi means on Fridays or every Friday.

In French, le + day of the week often expresses a habitual action:

• Le lundi, je travaille à la maison. = On Mondays, I work from home.

If you say just vendredi, that usually refers more to this Friday or Friday in a specific case, depending on context.

So here, le vendredi suggests a regular schedule:

• the daycare closes earlier every Friday

Here, alors means so, therefore, or as a result.

It connects the two ideas:

• the daycare closes earlier on Fridays
• so the parents have to arrive before 6 p.m.

It is a very common linking word in French.

Il faut que means it is necessary that or more naturally here, have to / must.

So:

• il faut que les parents arrivent = the parents have to arrive / the parents must arrive

French often uses this impersonal structure where English uses must or have to.

Compare:

• Il faut partir. = We must leave / It is necessary to leave
• Il faut que tu partes. = You must leave / It is necessary that you leave

Because il faut que is normally followed by the subjunctive.

The verb here is arriver, and the subjunctive form for ils/elles is arrivent:

• il faut que les parents arrivent

This is one of the most important patterns in French:

• il faut que + subjunctive

Examples:

• Il faut que tu viennes.
• Il faut que nous partions.
• Il faut qu’ils arrivent avant six heures.

For learners, one tricky point is that arrivent is spelled the same as the present indicative they arrive, but here it is functioning as the subjunctive because of il faut que.

Les parents means the parents in a general, situational sense.

In context, it means the parents of the children at the daycare. French often uses the definite article where English might use a possessive or leave it more implicit.

So les parents here is perfectly natural:

• the parents have to arrive before six

If you said leurs parents, that would mean their parents, and you would usually need a clearer reference for their.

Because French tells clock time with heure(s), and after numbers greater than one, it is plural.

So:

• une heure
• deux heures
• six heures

That is why the sentence says:

• avant six heures

This is the standard way to say before six o’clock.

Du soir means in the evening.

French often adds a part of the day after the time when it is helpful to make clear whether it is a.m. or p.m.:

• six heures du matin = 6 a.m.
• six heures du soir = 6 p.m.

So:

• avant six heures du soir = before 6 p.m.

Without du soir, six heures could be ambiguous unless the context already made it obvious.

Yes. 18 heures is also correct.

French uses both the 12-hour style and the 24-hour style:

• six heures du soir
• 18 heures

In everyday speech, many people prefer six heures du soir. In schedules, official notices, and more formal contexts, 18 heures is very common.

So this sentence could also be:

• ... avant 18 heures.

Not exactly. Avant six heures du soir means before 6 p.m.

That means any time earlier than 6:00:

• 5:50
• 5:30
• 4:45

If you wanted to emphasize exactly 6:00, French could add something like:

• avant six heures précises

But in this sentence, the normal meaning is simply before 6 p.m.

It breaks into two main parts:

1. La crèche ferme plus tôt le vendredi

   • La crèche = the daycare
   • ferme = closes
   • plus tôt = earlier
   • le vendredi = on Fridays

2. alors il faut que les parents arrivent avant six heures du soir

   • alors = so
   • il faut que = it is necessary that / must
   • les parents arrivent = the parents arrive
   • avant six heures du soir = before 6 p.m.

So the logic is: The daycare closes earlier on Fridays, so the parents must arrive before 6 p.m.