Cause and Purpose Clauses

In brief

To explain why something happens, use perché (‘because’) followed by a normal verb form. To say what you want to achieve, choose a purpose expression instead. Italian distinguishes a reason from a goal even when English uses ‘because’ or ‘so that’ in similar-looking sentences.

Form

Cause: perché + indicative; siccome + indicative (usually at the start). Purpose with the same subject: per + infinitive. Purpose involving another subject: in modo che + subjunctive.

Usage

• Use perché to give a reason: the following clause says what caused the action.
• Start with siccome when the reason sets up the rest of the sentence; it means ‘since’ or ‘as’.
• Use per + infinitive for the aim of the person doing the main action, without repeating the subject.
• Use in modo che + subjunctive when the intended result involves someone else.

Examples

• Resto a casa perché piove. — I’m staying home because it’s raining.
• Siccome piove, prendiamo l’autobus. — Since it’s raining, we’re taking the bus.
• Studio ogni giorno per migliorare il mio italiano. — I study every day to improve my Italian.
• Parlo piano in modo che i bambini possano dormire. — I speak quietly so that the children can sleep.

Common mistake

❌ Studio perché superare l’esame.

✅ Studio per superare l’esame.

For your own goal, use per + infinitive (‘to pass’). Perché cannot be followed directly by an infinitive here.

Remember

Perché gives a reason; per + infinitive gives the same person’s goal.