Learn Hardcore French: À son avis, le plus difficile était d’attendre aux urgences sans savoir, dans chaque cas, quand on serait soigné. - In his opinion, the hardest part was waiting in the emergency room without knowing, in each case, when one would be treated.

Selon lui/elle can sound a bit more formal, or like you’re reporting someone’s opinion.
À son avis can feel a bit more like you’re talking from inside the person’s point of view, though in everyday speech they often overlap.

The sentence could work without it:

Le plus difficile était d’attendre aux urgences…

But then you lose the explicit idea that this is that person’s subjective view.

Why is it son avis and not sa avis or something else?

In French, the possessive adjective agrees with the gender and number of the noun, not the owner.

avis is masculine singular.
So we must use son (masculine singular), regardless of whether the person is male or female.

Examples:

son avis (his/her opinion)
son stylo (his/her pen)
sa voiture (his/her car; because voiture is feminine)
ses amis (his/her friends; because amis is plural)

So À son avis = In his/her opinion.

Why is it le plus difficile était d’attendre and not something like c’était le plus difficile d’attendre?

French usually prefers the structure:

Le plus difficile, c’est / c’était de + infinitive
or Le plus difficile était de + infinitive

So:

Le plus difficile était d’attendre aux urgences… ✔️
Le plus difficile, c’était d’attendre aux urgences… ✔️ (a bit more oral / informal)
C’était le plus difficile d’attendre… ❌ sounds wrong/unnatural in French.

In French, when you define what is difficult, you typically put:

[Ce qui est difficile] + est / c’est + de + infinitive

Examples:

Le plus pénible, c’était de ne rien dire.
Le plus important, c’est de rester calme.

Why do we say d’attendre and not à attendre or just attendre?

After être + adjective / superlative (here: le plus difficile), French normally uses:

de + infinitive

So:

Le plus difficile est de comprendre.
Il est important de partir tôt.
C’est facile de dire ça.

Therefore:

Le plus difficile était d’attendre… ✔️

À attendre would be wrong here. The infinitive needs de after this structure.

You also can’t just drop the de:

Le plus difficile était attendre… ❌ incorrect.

Why is it attendre aux urgences and not attendre dans les urgences or something else?

Attendre = to wait (you don’t need a preposition like pour the way you do with to wait for in English).

Les urgences is the French way to say the emergency room / A&E / ER, literally the emergencies.

When you talk about being at the emergency department, French usually uses:

aux urgences = at the ER / in A&E

So:

J’ai dû attendre trois heures aux urgences. = I had to wait three hours in A&E.

You wouldn’t normally say:

attendre dans les urgences ❌ sounds wrong/unnatural.

aux = à + les, used because urgences is plural:

à + les urgences → aux urgences

Why is urgences in the plural? Why not à l’urgence?

In French, the hospital department is almost always referred to in the plural:

les urgences = the emergency department / casualty / A&E

Historically, it’s like saying emergency cases, and the plural stuck as the conventional name of the service.

So:

aux urgences (at the ER) is standard.
à l’urgence would be understood but sounds odd or non-standard in most varieties of French.

This is similar to set expressions like:

les toilettes (the toilet/bathroom) – always plural in French
les fiançailles (engagement) – also used in the plural

How does sans savoir work? Why isn’t there a subject like sans qu’on sache?

Sans + infinitive is a very common structure in French:

sans savoir = without knowing
sans parler = without speaking
sans rien dire = without saying anything

It’s impersonal; the subject is understood from context, often the same as the main subject:

Il est parti sans dire au revoir.
- He left without saying goodbye.
- We understand that he is the one not saying goodbye.

You could use a subordinate clause with sans que:

sans qu’on sache quand on serait soigné

But then you have to use the subjunctive (sache), and the style becomes more formal/complex. Sans savoir is simpler and more natural in everyday use.

What is the role of dans chaque cas here? Could it be placed somewhere else?

Dans chaque cas = in each case / in each instance.

In the sentence:

… sans savoir, dans chaque cas, quand on serait soigné.

it adds the nuance that every time they went to the ER, they didn’t know when they would be treated.

You could also place it:

… sans savoir quand, dans chaque cas, on serait soigné.
… sans savoir quand on serait soigné, dans chaque cas. (less elegant)

The original placement, between commas, makes it feel like a side comment (a parenthetical phrase), which is stylistically smooth.

The commas show that dans chaque cas is an extra piece of information, not grammatically required but semantically helpful.

Why is it quand on serait soigné (conditional) and not quand on sera soigné (future)?

This is a classic case of future-in-the-past / reported thought.

The person’s original, immediate question in the ER is:

Je me demande quand je serai soigné. (future: sera(i))

But the sentence is telling this story from a later point in time, looking back. In French, when you report a future from a past viewpoint, you often use the conditional:

Il se demandait quand il serait soigné.
- He was wondering when he would be treated.

So:

sans savoir … quand on serait soigné = without knowing when one would be treated.

If you said quand on sera soigné, it would sound like you’re still standing in the present at the ER right now or giving a general rule, which doesn’t match the past perspective of était (was).

Why is on used in quand on serait soigné instead of nous or les patients?

In French, on is extremely common in spoken and written language. It often corresponds to:

we
you (general “you/people in general”)
people / one
or even they in some contexts

Here, on is a general subject: it can mean any patient / you / we / people in that situation.

Alternatives:

quand nous serions soignés – grammatically correct, but sounds more formal or specifically about us as a group.
quand les patients seraient soignés – more explicit but heavier.

Using on:

keeps it generic
sounds natural and idiomatic

So:

On serait soigné ≈ you/we/people would be treated.

How does the passive on serait soigné work, and why is it soigné and not soignés / soignée?

Être soigné is the passive form of soigner (to treat, to care for medically):

Le médecin soigne le patient. (active)
Le patient est soigné par le médecin. (passive)

In the sentence:

on serait soigné = one/you/we would be treated.

About agreement:

soigné is a past participle used with être, so normally it agrees with the subject:
- il serait soigné (masc. sg.)
- elle serait soignée (fem. sg.)
- ils seraient soignés (masc. pl.)
- elles seraient soignées (fem. pl.)

But on is treated by default as masculine singular for agreement, unless you insist on a specific feminine agreement (in writing, usually with adjectives or participles describing a clearly feminine group).

So:

on serait soigné is grammatically masculine singular by default; that’s the standard form, even though on refers in reality to people of all genders.

Could the sentence be written as Le plus difficile, c’était d’attendre aux urgences…? Would that change the meaning?

Yes, you could say:

À son avis, le plus difficile, c’était d’attendre aux urgences sans savoir…

This is very natural, especially in spoken French.

Difference in nuance:

Le plus difficile était d’attendre… sounds a bit more written, slightly more formal or neutral.
Le plus difficile, c’était d’attendre… adds a little oral, conversational feel (because of c’était).

The meaning is effectively the same: the hardest thing was waiting….