Presente
What is happening now, habits, general truths, and plans: domani parto.
- accade
- accadono
Accadere
to happen
Irregular verb, gerund accadendo, past participle accaduto, auxiliary essere.
Newbie
Enough to talk about now, your plans, and the past.
Passato prossimo
The everyday past for a finished action: avere or essere plus the participle.
- è accaduto
- sono accaduti
Imperfetto
Past habits, descriptions, and what was going on.
- accadeva
- accadevano