Conditional perfect


The conditional perfect is a grammatical construction that combines the conditional mood with perfect aspect. A typical example is the English would have written. The conditional perfect is used to refer to a hypothetical, usually counterfactual, event or circumstance placed in the past, contingent on some other circumstance. Like the present conditional, the conditional perfect typically appears in the apodosis in a conditional sentence.

English

In English, the conditional perfect is formed using would have together with the past participle of the main verb. The auxiliary would marks the conditional mood, while the auxiliary have marks the perfect aspect. The conditional perfect is used chiefly in the main clause of "third conditional" sentences, as described under English conditional sentences. Examples:
  • You would have got more money if you had worked harder.
  • If we had run faster, we would have arrived earlier.
  • If I were a woman, I would have entered the contest.
It is also possible for the auxiliary would to be replaced by the modals should, could or might to express appropriate modality in addition to conditionality.
Sometimes, in informal speech, the would have construction appears in the if-clause as well, but this is considered incorrect in formal speech and writing.
English also has a conditional perfect progressive. For more details on the usage of this and of the ordinary conditional perfect, see the relevant sections of the article Uses of English verb forms.

Other languages

expresses past counterfactual conditional sentences in exactly the same way as English does: the if clause uses the had + past participle form, while the then clause uses the would have + past participle form, where the equivalent of would have is the conditional of the auxiliary used in all perfect constructions for the verb in question. Example:
  • Si on l'avait su , on aurait pu l'empêcher.
Spanish forms the conditional perfect on similar principles, e.g. yo te habría dicho todo.
Dutch has a similar tense to the English one, formed with zou/''zouden, the past tense of zullen, the auxiliary of the future tenses, e.g. ik zou je alles gezegd hebben. In Dutch grammar it is called the "perfect past future tense", emphasizing that it also has future-in-past properties.
Some eastern Finnic languages, such as Veps, Ludic and Livvi-Karelian, have come up with a conditional perfect suffix totally foreign to other Finnic languages. In Livvi-Karelian, for example, the conditional perfect suffix is -nuzi-''.
For certain other languages, see conditional mood.