How do I form the conditional past (conditionnel passé)?

If you know how to form the passé composé and how to form the conditional, then you're only one step away from knowing how to form the conditional past. I'm going to start with je mange and explain how to form the conditional past with it. Step 1) What auxiliary verb does it take? manger takes avoir in the passé composé the same rule applies if the verb in question takes être as an auxiliary in the passé composé Step 2) Conjugate this into the conditional mood for the singular first person, avoir becomes aurais Step 3) Add the past participle of your verb the past participle of manger is mangé if your verb uses être, the past participle follows the same gender & quantity agreement rules as in the passé composé Step 4) Put together the subject pronoun, the auxiliary verb (in the conditional) and the past participle: j' + aurais + mangé Subject pronoun + avoir/être in the conditional mood + past participle (with être agreement if necessary) And you're done!