Learn Italian: Dopo aver comprato i gettoni, abbiamo scoperto lo sbaglio. - After buying the tokens, we discovered the mistake.

In English, we often say "after buying," using the -ing form. In Italian, when you want to express that you did something after a completed action, you must use dopo plus the past infinitive. This is formed with the infinitive of the helper verb (avere or essere) plus the past participle (comprato). It translates literally to "after having bought."

Why is the 'e' missing at the end of aver?

When forming the past infinitive, the helper verbs avere and essere almost always drop their final -e. So, avere becomes aver. This is done simply because aver comprato flows more smoothly when spoken and is easier to say!

Is scoperto an irregular past participle?

Yes, scoperto is the irregular past participle of scoprire (to discover). It follows the same pattern as aprire (to open), which becomes aperto. If it were a regular -ire verb, it would end in -ito, but verbs ending in -oprire or -aprire often use this -erto ending.

Why is it lo sbaglio instead of il sbaglio?