Only the stem is irregular
The six endings -ais, -ais, -ait, -ions, -iez, -aient apply to every verb without exception. Only the stem in front of them is irregular, and it is the same one as in the futur simple: if you can say je serai, you can say je serais. Every one of these stems ends in -r.
The most important irregular stems
Infinitive and conditional (je)
| Infinitive | Conditionnel | Meaning |
|---|---|---|
| avoir | j'aurais | I would have |
| être | je serais | I would be |
| aller | j'irais | I would go |
| faire | je ferais | I would do |
| pouvoir | je pourrais | I could |
| devoir | je devrais | I should |
| vouloir | je voudrais | I would like |
| savoir | je saurais | I would know |
| venir | je viendrais | I would come |
| voir | je verrais | I would see |
Stem and ending marked separately
Irregular stems in a sentence
J'aurais besoin d'un conseil.
I'd need some advice.
Ce serait plus simple comme ça.
It would be simpler like that.
J'irais bien à la mer ce week-end.
I'd quite like to go to the seaside this weekend.
Pourrais-tu m'envoyer le document ?
Could you send me the document?
Elle viendrait avec plaisir, mais elle travaille.
She'd gladly come, but she's working.
Tu devrais y réfléchir.
You should think about it.
The impersonal classics
Three impersonal expressions almost always appear in the conditional in everyday speech. Il faut partir sounds like an order, il faudrait partir like a suggestion. The stems are faudr- (falloir) and vaudr- (valoir).
Three everyday formulas
il faudrait
we should, one ought to
il vaudrait mieux
it would be better
il y aurait
there would be
Il faudrait réserver assez tôt.
We should book early enough.
Il vaudrait mieux partir maintenant.
It would be better to leave now.
Il y aurait une solution plus simple.
There would be a simpler solution.
Verbs with a spelling change
These verbs have no new stem, but their spelling changes in front of the ending, in all six persons including nous and vous: nous achèterions.
Spelling change in the conditional
| Infinitive | Conditionnel | Change |
|---|---|---|
| acheter | j'achèterais | e → è |
| appeler | j'appellerais | l → ll |
| payer | je paierais | y → i (payerais is also correct) |
J'achèterais cette voiture si elle était moins chère.
I'd buy this car if it were cheaper.
Je t'appellerais plus souvent avec un meilleur réseau.
I'd call you more often with better reception.
