Rule reminder

When a relative clause modifies an indefinite or non-existent antecedent (someone, anyone, no one, something), or when you are searching for something whose existence is uncertain, use the subjunctive. Compare: 'Ho trovato qualcuno che SA parlare italiano' (I found someone who CAN speak Italian — definite, he exists) vs 'Cerco qualcuno che SAPPIA parlare italiano' (I'm looking for someone who can speak Italian — indefinite, not yet found).