French Conditional Past
Le Conditionnel Passé is the past tense of the conditional mood, which expresses actions that would have or might have happened in the past. It's about missed opportunities and unrealized potential.
The English past conditional is formed with the verbs ''would have'' + the past participle of the main verb, while in French it's formed with avoir or être in le conditionel présent+ the past participle of the verb.
Je serais allé en Australie si j'avais eu les moyens.I would have gone to Australia if I could have afforded it.
See also: French Passé and All French tenses