The Three Types of Conditional Sentences

Italian conditional sentences (Periodo Ipotetico) consist of a condition (the se clause) and a consequence (the main clause). They are divided into three types based on probability.

1. Periodo Ipotetico della Realtà (Real / Likely)

Used for likely or factual conditions. It typically uses Indicativo in both clauses (Presente or Futuro).
Se piove, prendo l'ombrello. (If it rains, I take the umbrella.)

2. Periodo Ipotetico della Possibilità (Possible / Hypothetical)

Used for improbable or imaginary present/future situations. It uses Se + Congiuntivo Imperfetto, and the main clause takes the Condizionale Presente.
Se avessi tempo, viaggerei di più. (If I had time, I would travel more.)

3. Periodo Ipotetico dell'Irrealtà (Impossible / Past)

Used for past situations that cannot be changed. It uses Se + Congiuntivo Trapassato, and the main clause takes the Condizionale Passato.
Se fossi partito ieri, sarei arrivato in orario. (If I had left yesterday, I would have arrived on time.)