Rule reminder
Consecutive clauses answer 'with what result?' and use indicative or infinitive. Final (purpose) clauses answer 'with what aim?' and use 'affinché/perché + subjunctive' or 'per + infinitive'. Do not confuse the two: 'talmente...che' = result; 'affinché' = purpose.
Ha parlato lentamente _____ i partecipanti stranieri capissero ogni parola. (purpose)