Troisième conditionnel

Introduction

On utilise le troisième conditionnel pour décrire des situations irréelles au passé et leurs résultats imaginaires. La situation et le résultat existent tous deux dans le passé; la situation ne s'est pas déroulée donc le résultat est impossible:

If I had woken up earlier, I wouldn’t have missed the train.

"If I had woken up earlier" ("Si je m'étais réveillé plus tôt") est la situation irréelle.
"I wouldn’t have missed the train" ("Je n'aurais pas raté le train") est le résultat imaginaire.

La situation réelle et le résultat: I didn’t wake up earlier so I missed the train (Je ne me suis pas réveillé plus tôt donc j'ai raté le train).

Exemples:

If she hadn't got the job, she would have been very disappointed.
La situation réelle et le résultat: She got the job so she wasn’t disappointed (Elle a décroché l'emploi donc elle n'a pas été déçue).
If they had known about the problems with the trains, they would have driven.
La situation réelle et le résultat: They didn’t know about the problems with the trains so they didn’t drive (Ils ne savaient pas qu'il y avait des problèmes avec les trains donc ils n'ont pas pris la voiture).
Would I have got sick if I hadn’t eaten the fish?
La situation réelle et le résultat: I ate the fish. Was that why I got sick? (J'ai mangé le poisson. Est-ce pour ça que j'ai été malade?)

Formation

On forme le troisième conditionnel avec une proposition conditionnelle et une proposition principale:

Proposition conditionnelle: "if" + plus-que-parfait (past perfect)
Proposition principale: "would have" + participe passé

L'ordre des propositions n'est pas important: le sens est le même.

Si on met la proposition conditionnelle avant la proposition principale, on utilise une virgule:

Proposition conditionnelle	Proposition principale
"If" + plus-que-parfait (past perfect) + virgule	"would have" + participe passé
If I’d woken up earlier,	I wouldn’t have missed the train.
If she hadn’t got the job,	she would have been very disappointed.
If they had known about the problems with the trains,	they would have driven instead.
If I hadn’t eaten the fish,	would I have got sick?

On n'utilise pas de virgule si on met la proposition principale avant la proposition conditionnelle:

Proposition principale	Proposition conditionnelle
"would have" + participe passé	"if" + plus-que-parfait (past perfect)
I wouldn’t have missed the train	if I had woken up earlier.
She would have been very disappointed	if she hadn’t got the job.
They would have driven	if they had known about the problems with the trains.
Would I have got sick	if I hadn’t eaten the fish?

On peut contracter le pronom sujet et "would": "I’d" / "you’d" / "we’d" / "they’d" / "she’d" / "he’d" / "it’d"
On peut contracter "would" et "have": would’ve
On peut utiliser le plus-que-parfait continu dans la proposition conditionnelle:
If I’d been looking more carefully, I would have noticed the mistake.
Je n'ai pas remarqué la faute parce que je ne faisais pas assez attention.

Exercices d'entraînement

.

1)

They’d have passed their exams if they harder. (study)

2)

If he had followed the directions, he on time. (arrive)

3)

Would you have guessed the ending of the film if you the book. (not read)

4)

Sarah would to Paris if she’d had enough time. (go)

E xercices d'entraînement supplémentaires

Complétez les phrases pour former le troisième conditionnel en choisissant la réponse correcte entre a, b, c ou d:
.

1)

If he had known it was her birthday, he would ____ her a present.

had bought

have buy

have bought

had buy

2)

They wouldn’t have gone if they ____ it would be so crowded.

'd knew

had knows

'd know

had known

3)

Would you ____ to the conference if the company hadn’t paid for the tickets?

have gone

have went

had gone

had went

4)

I would ____ meat if I had known that you are vegetarian.

not had cook

n't have cooked

n't have cook

not had cooked

5)

If I ____ the menu, I wouldn’t have gone to the restaurant.

had saw

had seen

have saw

have seen

6)

If they ____ a map, would they have got lost?

had buy

have buy

have bought

had bought

Utilisation de "could", "might"

On peut utiliser "could" ou "might" au lieu de "would" dans la proposition principale du troisième conditionnel.

If they had known about the problems with the trains, they would have driven.
La proposition principale avec "would" décrit un résultat certain.
If they had known about the problems with the trains, they could have driven.
La proposition principale avec "could" décrit un résultat possible d'une capacité de faire quelque chose.
If they had known about the problems with the trains, they might have driven.
La proposition principale avec "might" décrit un résultat possible.