There are 3 main types of conditional or hypothetical sentences i.e. 'if-clause's || TYPE 1: 'if this happens, this will happen': present + present e.g. se piove, non esco OR future + future e.g. se verrai con me, ti mostrerò una sorpresa OR present + future e.g. se parti domani, sarò triste || TYPE 2: 'if this happened, this would happen': imperfect subjunctive + present conditional e.g. se avessi tempo ti aiuterei || TYPE 3: 'if this had happened, this would have happened': imperfect subjunctive + past conditional e.g. se me lo avessero detto, sarei venuta subito