Learn Hardcore French: Quand elle se rendort, Paul ronfle doucement à côté d’elle. - When she falls back asleep, Paul snores softly next to her.

So elle se rendort literally means she re‑falls asleep (she puts herself to sleep again). The se shows that the action is done by the subject to itself and is also simply part of the verb’s normal form.

Is se rendormir an irregular verb? How is it conjugated in the present tense?

Yes, se rendormir is based on dormir, which is irregular.

Present tense of se rendormir:

je me rendors
tu te rendors
il / elle / on se rendort
nous nous rendormons
vous vous rendormez
ils / elles se rendorment

In the sentence, elle se rendort is the third person singular present tense form.

Could we say Quand elle s’endort instead of Quand elle se rendort?

No, not with the same meaning.

s’endormir = to fall asleep (for the first time)
- Elle s’endort. = She is falling asleep.
se rendormir = to fall asleep again / to go back to sleep
- Elle se rendort. = She is going back to sleep.

If you used Quand elle s’endort, it would mean When she falls asleep (the first time), not when she goes back to sleep.

Why is quand used here? Could we use lorsque instead?

Quand and lorsque are very close in meaning and often interchangeable when they mean when (in a temporal sense).

Quand elle se rendort, Paul ronfle…
Lorsqu’elle se rendort, Paul ronfle…

Both are grammatically correct. Lorsque can sound a bit more formal or literary; quand is more common in everyday speech.

Note that with lorsque, you must elide before a vowel: lorsqu’elle, not lorsque elle.

How do you pronounce Quand elle se rendort? Are there any liaisons?

Slow phonetic approximation:

Quand ≈ kɑ̃ (nasal an, final d is silent)
elle ≈ ɛl
se ≈ sə
rendort ≈ ʁɑ̃dɔʁ (nasal an, final t is silent)

Together: Quand elle se rendort ≈ kɑ̃ tɛl sə ʁɑ̃dɔʁ

There is a liaison between quand and elle, so you hear a t sound: kan‑tel.
No liaison inside se rendort; just pronounce them smoothly one after the other.

What does ronfle come from, and what does ronfler mean?

Ronfle is the third person singular present of the verb ronfler.

ronfler = to snore
- Je ronfle. = I snore.
- Paul ronfle. = Paul snores / is snoring.

In this sentence, Paul ronfle doucement means Paul is snoring softly. Ronfler is an intransitive regular -er verb.

Why is doucement placed after ronfle? Could it go somewhere else?

Doucement is an adverb of manner (it describes how he snores). In French, these adverbs usually come right after the verb:

Paul ronfle doucement.

Other possible orders:

Paul doucement ronfle. – Grammatically possible but sounds literary or marked.
Doucement, Paul ronfle… – Possible, but now doucement is more like a sentence adverb (changing the rhythm or emphasis).

The most natural everyday order is exactly what you have: ronfle doucement.

Does doucement here mean softly, slowly, or gently?

Doucement can mean several things depending on context:

softly / quietly (low volume)
gently (without force)
slowly

Here, with ronfle, it most naturally means softly / quietly:
Paul ronfle doucement ≈ Paul is snoring softly / quietly.

What does à côté d’elle literally mean, and how is it different from près d’elle?

Literally:

à côté de = beside / next to
près de = near / close to

So:

à côté d’elle = next to her / beside her (right by her side)
près d’elle = near her / close to her (in her vicinity, not necessarily directly beside)

In a context like two people in bed, à côté d’elle suggests right beside her on the bed, which fits the image of someone snoring next to her.

Why is it written d’elle and not de elle?

French uses elision: when a small word ending in a vowel comes before a word starting with a vowel or silent h, the vowel is dropped and replaced by an apostrophe.

de + elle → d’elle
de + elle is never written in standard French.

The same happens with à + elle → à elle (no elision here, because à is just one letter), but with de, you must write d’elle.

Is the comma after Quand elle se rendort necessary?

In French, when a subordinate clause comes before the main clause, it is normal and recommended to put a comma:

Quand elle se rendort, Paul ronfle doucement à côté d’elle.

If the order is reversed, there is usually no comma:

Paul ronfle doucement à côté d’elle quand elle se rendort.

So in the original sentence, the comma is standard and stylistically correct.

How would this sentence look in a past tense, like the imparfait or passé composé?

Some natural possibilities:

More descriptive / background (imparfait + imparfait):
- Quand elle se rendormait, Paul ronflait doucement à côté d’elle.
  = When she was going back to sleep, Paul was snoring softly beside her.
Completed action before another (passé composé + imparfait):
- Quand elle s’est rendormie, Paul ronflait doucement à côté d’elle.
  = When she had gone back to sleep / when she went back to sleep, Paul was snoring softly beside her.

Note in s’est rendormie:

The auxiliary is être (because it’s reflexive).
The past participle rendormi agrees in gender and number with elle, so it becomes rendormie.