Les modaux ont la même forme à toutes les personnes ; ils n'ont pas d'infinitif ; ils sont suivis de la base verbale ; ils se conjuguent sans auxiliaire.
1 Les principaux modaux et leurs équivalents
Pour certains temps, il faut utiliser des équivalents que l'on peut conjuguer.
► Can ou be able to expriment la capacité.
| He can swim. [présent] He could swim. [prétérit] | ▶
▶ | He will be able to swim. [expression de l'avenir] He has been able to swim. [present perfect] |
► Must ou have to expriment l'obligation.
| I must wear a uniform. [présent] | ▶ | You'll have to wear a uniform. [expression de l'avenir] |
Attention ! Musn't exprime l'interdiction. Don't have to exprime l'absence d'obligation.
► May ou be allowed to expriment la permission.
You may to go to the party.
Tu peux aller à la soirée.
► May et be likely to (il est probable que) expriment la probabilité.
She is likely to come. Ou : She may come.
Il est probable qu'elle vienne.
Attention ! La probabilité dans le futur s'exprime avec will ('ll) + probably/possibly/maybe/certainly/perhaps.
They'll probably come next week.
Ils viendront probablement la semaine prochaine.
Maybe/Perhaps they will come next week.
Ils viendront peut-être la semaine prochaine
2 Modal + have + participe passé
► Could have + participe passé : possibilité dans le passé
I could have helped her. J'aurais pu l'aider.
► Should have + participe passé : reproche
You should have told me. Tu aurais dû me le dire.
► Would have + p. passé : événement non réalisé dans le passé
I would have given you my e-mail address, if you had asked me.
Je t'aurais donné mon e-mail si tu me l'avais demandé.
3 Tableau récapitulatif
| can/could | |
| permission | Can I smoke here? |
| absence de permission | You can't smoke here. |
| capacité physique capacité intellectuelle | He can lift this weight. He can speak five languages. |
| incapacité | I couldn't do this exercise. |
| demande polie | Can/Could you pass me the water? |
| impossibilité | He can't be the thief. |
| must | |
| obligation | You must be here before 10. |
| interdiction | You mustn't walk on the grass. |
| déduction | You must be tired. |
| may/might | |
| probabilité | She may/might come. |
| suggestion | We might visit the museum. |
| permission | May I come in? |
| should/ought to | |
| conseil | You should/ought to smoke less. |
| shall | |
| suggestion | Shall we go to the cinema? |
| will | |
| expression de l'avenir | I'll go to Rome next week. |
| suggestion | Will you do it for me? |
| would | |
| conditionnel | I would lend you money if I had some. |
| demande polie | Would you carry my bag, please? |
| souhait | I would like to travel more. |