La salle d’attente se remplit vite le matin.

In French, you usually need an article before a singular countable noun, so la salle d’attente is the normal way to say the waiting room.

French uses articles more often than English. Where English might sometimes drop the, French usually keeps it.

• la salle d’attente = the waiting room
• une salle d’attente = a waiting room

So la here is just the definite article.

d’ is just de shortened before a vowel.

• de + attente → d’attente

This shortening is called elision. French often drops the vowel of small words like de, le, je, etc. before a word starting with a vowel sound.

So:

• de attente ❌
• d’attente ✅

Because d’attente is not really saying of the waiting in a literal sense. It is a fixed noun pattern that describes the type or purpose of the room.

So une salle d’attente means:

• a room for waiting
• a waiting room

French often uses noun + de/d’ + noun to classify something:

• une tasse de thé = a cup of tea
• une salle de bain = bathroom
• une salle d’attente = waiting room

You do not use de l’ here because attente is being used in a general, descriptive way, not as a specific instance of the waiting.

The verb here is se remplir, which means to fill up or to become full.

This is a pronominal (often called reflexive) form. In English, we often say:

• The waiting room fills up quickly in the morning.

French often expresses that idea with se + verb:

• La salle d’attente se remplit...

It does not mean the room is literally filling itself on purpose. It means the room becomes full.

Compare:

• Le personnel remplit la salle d’attente. = The staff fill the waiting room.
• La salle d’attente se remplit. = The waiting room fills up / becomes full.

Because remplit here is a verb, not an adjective.

In La salle d’attente se remplit, remplit is the third-person singular present tense of se remplir:

• je me remplis
• tu te remplis
• il/elle/on se remplit
• nous nous remplissons
• vous vous remplissez
• ils/elles se remplissent

Since the subject is la salle d’attente (singular), the verb form is se remplit.

By contrast, remplie is a past participle or adjective:

• La salle est remplie. = The room is full / filled.

So:

• se remplit = is filling up / fills up
• est remplie = is filled / is full

Yes, it is in the present tense.

Here, the present tense expresses a habit or general truth, not only something happening at this exact second.

So La salle d’attente se remplit vite le matin means something like:

• The waiting room fills up quickly in the morning.
• The waiting room tends to fill up quickly in the morning.

French uses the present tense a lot for repeated actions and regular patterns.

Because short adverbs like vite, bien, mal, souvent, etc. are often placed after the conjugated verb in simple tenses.

So:

• se remplit vite = fills up quickly

That is the most natural word order here.

You will often see this pattern:

• Il parle vite. = He speaks quickly.
• Elle travaille bien. = She works well.
• Le magasin ferme tôt. = The shop closes early.

Yes. Vite and rapidement both mean quickly.

• La salle d’attente se remplit vite le matin.
• La salle d’attente se remplit rapidement le matin.

Both are correct.

The difference is mostly tone:

• vite = very common, everyday, natural
• rapidement = a bit more formal or neutral

In ordinary speech, vite is extremely common.

French often uses le + time expression to mean in the ... when talking about a general time period.

So:

• le matin = in the morning / in the mornings
• le soir = in the evening
• l’après-midi = in the afternoon

In this sentence, le matin means in the morning, in a general habitual sense.

Compare:

• Je travaille le matin. = I work in the morning / in the mornings.
• La salle d’attente se remplit vite le matin. = The waiting room fills up quickly in the morning.

Because dans le matin is not the normal French way to say in the morning.

The standard expression is simply:

• le matin

French often uses a bare article with parts of the day in habitual expressions:

• le matin
• le soir
• l’après-midi

So for a learner, it is best to memorize le matin as the normal expression for in the morning.

Not really. This sentence focuses on what happens to the room itself: it fills up.

• La salle d’attente se remplit vite le matin. = The waiting room fills up quickly in the morning.

If you wanted to say that people are actively filling it, French would more likely use a different subject, for example:

• Les patients remplissent vite la salle d’attente le matin. = The patients quickly fill the waiting room in the morning.

So the se remplir version is the natural way to describe the room becoming full.

A simple pronunciation guide would be:

• La salle ≈ la sal
• d’attente ≈ da-tont
• se remplit ≈ suh rom-plee

A few notes:

• salle sounds like sal
• d’attente links smoothly because of the elision
• remplit ends with an ee sound: rom-plee
• the t in remplit is normally not pronounced

A rough full approximation:

la sal da-tont suh rom-plee veet luh ma-tan

That is only approximate, but it may help you hear the rhythm of the sentence.