English Conditionals and Modal Verbs: Forms, Uses & Examples
First Conditional
| If + present simple, | will + infinitive |
| Will + infinitive | If + present simple |
Use
- To discuss possible or probable future events.
- To make promises and give warnings.
Second Conditional
| If + past simple, | would + infinitive |
| Would + infinitive | If + past simple |
Use
- To discuss imaginary situations in the present.
- To discuss imaginary or improbable events in the future.
Third Conditional
| If + past perfect, would have + past participle |
Use
- To discuss hypothetical past events (for example: events that did not happen).
Conditionals with Modals
Modal verbs can replace or accompany will / would in conditional sentences to change meaning (possibility, permission, ability, obligation, etc.).
- First conditional: may / might / can / must / should
- Second conditional: could / might
- Third conditional: could have / might have
Wishes and Regrets
- To express regrets about the past — wish + past perfect.
- To express a desire for the present — wish + could.
- To express dissatisfaction with what somebody is doing in the present (we don’t use this about ourselves) — wish + would.
Functions of Modal Verbs
(Modal verbs with a main verb add extra meaning.)
Prohibition
Can’t: students can’t use it. Mustn’t: children mustn’t talk in the corridors.
Permission
Can: You can wear your own clothes. Be allowed to: We’re allowed to watch this show.
Ability
Can: I can speak Italian. Could: He could understand everything. Be able to: They are able to come. Managed to: We managed to finish it.
Obligation
Must: You must obey the law. Have to: All students have to sit this exam. Need to: You need to wear smart clothes.
No Obligation
Don’t have to / Needn’t.
Advice
Should / Ought to / Had better.
Possibility
May / Might / Could.
Deduction
Can’t / Must.
Affirmative, Negative and Question Forms
Affirmative: Person + modal verb + infinitive (I can sing).
Negative: Person + modal verb + not + infinitive (I mustn’t sing).
Question: Modal verb + person + infinitive + ? (Should you sing?)
Modal Perfects
Affirmative
Person + modal verb + have + past participle.
(He might have gone to the cinema.)
Negative
Person + modal verb + not + have + past participle.
(You shouldn’t have opened the door.)
Question
Modal verb + person + have + past participle + ?
(Should she have told him yesterday?)