Fondamentaux
Qu'est-ce qu'un modal du passé ?

Les modaux du passé se construisent avec un modal suivi de have + participe passé. Ils permettent de porter, depuis le présent, un jugement sur un fait passé : déduction, regret, reproche, possibilité manquée ou hypothèse. On les retrouve partout dans les bilans et les analyses rétrospectives.

Le prétérit décrit un fait passé de façon neutre ; le modal du passé ajoute une nuance de certitude ou un jugement sur ce fait.

Règles de formation

Structure fixemodal + have + participe passé, jamais had : She should have called, et non should had called Have invariablequel que soit le sujet : he must have known, et non must has known Négatifmodal + not + have + participe : shouldn't have, couldn't have, can't have Have, pas ofà l'oral, have se réduit à /əv/ : on n'écrit jamais should of Un jugementpour un simple fait passé, sans jugement, on garde le prétérit ou le present perfect

Présent ou passé ? He must be tired : déduction sur le présent (il doit être fatigué). He must have been tired : déduction sur le passé (il devait être fatigué à ce moment-là).
Certitude sur le passé
Must have, can't have : la déduction

Must have + participe passé exprime une déduction forte sur un fait passé : pas de preuve directe, mais les indices rendent la conclusion quasi certaine. Son contraire n'est pas mustn't have mais can't have (ou couldn't have) : on est sûr que le fait n'a pas eu lieu.

Must have : sûrement
Sujet + must have + participe passé
The analyst must have made an error in the model.
They must have known about the risk beforehand.
Can't have : sûrement pas
Sujet + can't have + participe passé
He can't have signed the contract: he was abroad.
The board can't have approved this without a vote.
Couldn't have : impossible
Sujet + couldn't have + participe passé
She couldn't have finished the audit that fast.
The forecast couldn't have been more wrong.
May / might have : peut-être
Sujet + may / might have + participe passé
The delay may have been caused by a supply issue.
They might have underestimated demand.
Must have ou should have ? He must have left already : déduction, je pense que c'est le cas. He should have left already : il aurait dû partir (et ne l'a sans doute pas fait).
Jugement rétrospectif
Should have, shouldn't have : reproche et regret

Should have + participe passé exprime un regret ou un reproche pour une action souhaitable qui n'a pas eu lieu. Shouldn't have vise au contraire une action qui a eu lieu mais n'aurait pas dû. Ought to have est un équivalent plus soutenu de should have.

Should have : ce qui a manqué
Sujet + should have + participe passé
The firm should have diversified its portfolio sooner.
I should have double-checked the figures.
Shouldn't have : l'erreur commise
Sujet + shouldn't have + participe passé
They shouldn't have signed without legal advice.
We shouldn't have cut the marketing budget.
Ought to have : soutenu
Sujet + ought to have + participe passé
The board ought to have anticipated the downturn.
Management ought to have disclosed the conflict of interest.
01
Regret personnel
Regretter de ne pas avoir agi autrement.
I should have prepared more thoroughly for the interview. J'aurais dû mieux préparer l'entretien.
02
Reproche professionnel
Critiquer une décision prise, ou non prise, dans le passé.
The committee should have flagged the discrepancy immediately. Le comité aurait dû signaler l'anomalie tout de suite.
03
Action regrettée
Shouldn't have : critiquer ce qui a bel et bien été fait.
The bank shouldn't have approved the loan without collateral. La banque n'aurait pas dû accorder le prêt sans garantie.
Repère : should have pointe un manque (ce qui n'a pas été fait), shouldn't have une erreur commise (ce qui a été fait à tort).
Potentiel non réalisé
Could have, might have : possibilité et hypothèse

Could have + participe passé exprime une possibilité réelle qui existait dans le passé mais ne s'est pas réalisée. Might have (ou may have) exprime une hypothèse plus incertaine. Could have insiste sur l'occasion manquée, might have sur l'incertitude du scénario.

Could have : occasion manquée
Sujet + could have + participe passé
With better forecasting, we could have avoided the shortage.
The start-up could have secured funding earlier.
Might have : hypothèse incertaine
Sujet + might have + participe passé
The deal might have succeeded with more time.
A different strategy might have changed the outcome.
May have : hypothèse plausible
Sujet + may have + participe passé
The company may have overestimated demand.
Investors may have reacted too quickly.
Couldn't have : rien n'aurait pu
Sujet + couldn't have + participe passé
Nothing could have prepared them for that crisis.
We couldn't have predicted such volatility.
Could have ou might have ? The team could have won the contract : elle en avait les moyens, l'occasion est passée. The team might have won the contract : simple hypothèse, sans affirmer qu'elle en avait la capacité.
Irréel du passé
Would have : le conditionnel passé

Would have + participe passé exprime ce qui se serait produit si les circonstances passées avaient été différentes. C'est la conséquence de l'hypothèse irréelle du passé (leçon 21), très utile pour les raisonnements contrefactuels.

Would have : conséquence imaginée
Sujet + would have + participe passé
They would have invested with better information.
I would have taken a different approach.
Wouldn't have : négatif
Sujet + wouldn't have + participe passé
Without the bailout, the bank wouldn't have survived.
We wouldn't have met the deadline otherwise.
Would … have ? : interrogatif
Would + sujet + have + participe passé + ?
Would you have accepted the offer?
Would the board have approved a lower budget?
Phrase complète
If + sujet + past perfect + , + would have + participe
If we had reacted sooner, we would have limited the losses.
Rappel : l'hypothèse irréelle du passé

If + past perfect, puis would have + participe passé :
If the company had listened to analysts, it would have avoided the crisis. Si l'entreprise avait écouté les analystes, elle aurait évité la crise.

Nécessité après coup
Needn't have ou didn't need to ?

Les deux tournures signifient « il n'était pas nécessaire de », mais elles diffèrent sur un point essentiel : l'action a-t-elle eu lieu ? Avec needn't have + participe passé, l'action a été faite, et l'on constate après coup qu'elle était inutile. Avec didn't need to + base, l'action, en général, n'a pas été faite.

Needn't have : fait, mais inutile
Sujet + needn't have + participe passé
We needn't have hired extra consultants: the team managed fine.
You needn't have rushed: the deadline was extended.
Didn't need to : pas fait
Sujet + didn't need to + base
She didn't need to attend, so she stayed at home.
We didn't need to renegotiate: the terms were good.
Didn't have to : pas d'obligation
Sujet + didn't have to + base
The firm didn't have to lay off staff this quarter.
We didn't have to file an extension.
Structure
L'action a-t-elle eu lieu ?
Exemple
needn't have + participe
oui, mais elle était inutile
I needn't have printed the slides: the meeting was cancelled.
didn't need to + base
en général, non
I didn't need to print the slides, so I saved paper.
didn't have to + base
non : pas d'obligation
We didn't have to submit the form this year.
Synthèse
Récapitulatif et piège de prononciation

Voici l'ensemble des modaux du passé, classés par sens, pour une révision rapide.

Structure
Sens
Exemple
must have + participe
déduction (sûrement)
The data must have been corrupted.
can't have + participe
déduction (sûrement pas)
She can't have missed the email.
should have + participe
reproche, regret (manque)
They should have acted sooner.
shouldn't have + participe
reproche, regret (erreur)
He shouldn't have resigned so abruptly.
could have + participe
possibilité non réalisée
We could have avoided the loss.
might have + participe
hypothèse incertaine
The deal might have succeeded otherwise.
would have + participe
conditionnel passé
They would have invested with better information.
needn't have + participe
fait, mais inutile
We needn't have hired extra staff.
À l'oral : les formes contractées
should've/ˈʃʊdəv/
shouldn't've/ˈʃʊdntəv/
could've/ˈkʊdəv/
would've/ˈwʊdəv/
might've/ˈmaɪtəv/
must've/ˈmʌstəv/
Le piège du « of » : à l'oral, have se prononce presque comme of, d'où les graphies fautives should of, could of, would of, fréquentes même chez les anglophones. À l'écrit, c'est toujours have.
Pratique
Exercices
Exercice 1 Choisissez le modal du passé qui convient (écrivez modal + have + participe)
01.
The figures don't add up: someone (must have / should have) made a mistake.
→ must have made (déduction)
02.
We lost the client. We (should have / must have) responded faster.
→ should have responded (reproche)
03.
He (can't have / needn't have) read the report: he is asking basic questions.
→ can't have read (déduction : sûrement pas)
04.
I took an umbrella, but I (needn't have / can't have) taken it: it didn't rain.
→ needn't have taken (fait, mais inutile)
05.
With a bigger budget, the campaign (would have / must have) reached more customers.
→ would have reached (conséquence imaginée)
06.
The merger (might have / shouldn't have) gone differently if the CEO had negotiated harder.
→ might have gone (hypothèse incertaine)
Exercice 2 Complétez avec modal + have + participe passé
01.
The board (should / disclose) the conflict of interest earlier.
→ should have disclosed
02.
The accounts are perfect. They (can't / falsify) the report.
→ can't have falsified
03.
Without the subsidy, the factory (would / close) down.
→ would have closed
04.
We bought insurance, but we (needn't / buy) it: nothing went wrong.
→ needn't have bought
05.
He resigned right after the scandal broke: he (must / know) about it.
→ must have known
06.
The strategy failed. With more research, they (could / avoid) the mistake.
→ could have avoided
Exercice 3 Reformulez avec le modal indiqué
01.
I'm almost certain the analyst underestimated the risk. → must have
→ The analyst must have underestimated the risk.
02.
It was a mistake for the firm to ignore the warning signs. → shouldn't have
→ The firm shouldn't have ignored the warning signs.
03.
It's impossible that she approved this expense: she was on leave. → can't have
→ She can't have approved this expense.
04.
It was possible for us to win the contract, but we didn't. → could have
→ We could have won the contract.
05.
It wasn't necessary for us to renew the contract, but we did anyway. → needn't have
→ We needn't have renewed the contract.
06.
I regret not investing earlier. → should have
→ I should have invested earlier.