Learn Hardcore French: Au réveil, elle respire doucement pour calmer sa respiration et son cœur. - Upon waking, she breathes slowly to calm her breathing and her heart.

So the sentence means she does this right after she wakes up, as part of her waking-up moment or routine. It’s a fixed expression: Au réveil, … = “On waking up, …”

Is réveil a noun or a verb here? And why is it au not à?

In Au réveil, réveil is a noun, not a verb.

The verb “to wake up” is se réveiller.
The noun le réveil can mean:
- the act of waking up
- an alarm clock (depending on context)

Here it’s “the act of waking up,” so:

à + le réveil → au réveil

That’s why it’s au, the contraction of à + le.

What is the role of the comma in Au réveil, elle respire…? Could I say it without the comma?

The comma separates an introductory time expression from the main clause.

Au réveil, elle respire doucement… = “On waking up, she breathes slowly…”

You could write it without the comma (Au réveil elle respire…) and it’s still understandable, but standard written French normally uses the comma after such an introductory phrase. It helps the reader see the structure more clearly.

What’s the difference between respirer and respiration in this sentence?

respirer = to breathe (verb)
la respiration = breathing (as a noun), or “breath” in a general sense

So:

elle respire doucement = she breathes slowly
pour calmer sa respiration = to calm her breathing

Using both the verb respire and the noun respiration in one sentence is normal and not considered awkward in French here.

What does doucement mean, and what kind of word is it?

doucement is an adverb. It comes from the adjective doux / douce (soft, gentle, sweet).

Its meanings include:

gently
softly
slowly / quietly (depending on context)

In this sentence:

elle respire doucement ≈ “she breathes slowly/gently”

It describes how she breathes.

How does pour calmer work here? Is it like “in order to calm”?

Yes. pour + infinitive is a very common way to express purpose in French.

pour calmer sa respiration et son cœur =
- “to calm her breathing and her heart”
- or “in order to calm her breathing and her heart”

So the structure is:

[Main action] + pour + [infinitive showing the purpose]
Elle respire doucement pour calmer…
= She breathes slowly in order to calm…

Why is it sa respiration and son cœur? I thought the possessive agreed with the owner, not the noun.

In French, son / sa / ses agree with the gender and number of the noun possessed, not with the owner.

respiration is feminine singular → sa respiration
cœur is masculine singular → son cœur

Both are “her” in English, but French marks the gender of the thing possessed:

sa respiration = her breathing (breathing = feminine noun)
son cœur = her heart (heart = masculine noun)

Could I say pour se calmer instead of pour calmer sa respiration et son cœur? What’s the difference?

Yes, you could say pour se calmer, but it’s less specific.

pour calmer sa respiration et son cœur
focuses on physical aspects: her breathing and her heartbeat.
pour se calmer
means “to calm herself down” in a more general, global sense (emotionally, physically, mentally).

Both are correct; the original just spells out what she is calming.

Does son cœur mean “heart” in a physical sense, or can it also be emotional (like feelings)?

It can be both, depending on context.

Literally, son cœur = her heart (physical organ / heartbeat).
Figuratively, cœur often refers to feelings, emotions, courage, inner self.

In this sentence, because it’s paired with sa respiration (breathing), the first interpretation is physical (heart rate). But readers may also sense a slight emotional nuance: calming both body and emotions.

Is the present tense here describing a habit, or something happening right now?

French présent can describe:

An action happening now
A habitual action or routine

In this sentence, without extra context, it most naturally reads as habitual:

Au réveil, elle respire doucement…
= “When she wakes up, she (usually) breathes slowly…”

So it sounds like something she regularly does each time she wakes up.

Could I change the word order to Elle respire doucement au réveil…? Does it sound different?

Yes, you can say:

Elle respire doucement au réveil pour calmer sa respiration et son cœur.

This is still correct and natural. The difference is subtle:

Au réveil, elle respire doucement…
puts more emphasis on the time frame (“On waking up…”).
Elle respire doucement au réveil…
focuses first on what she does, and then specifies when.

Both are fine; the original is a common stylistic choice to set the scene.