CILS is the Università per Stranieri di Siena's Italian proficiency certification, spanning A1 through C2 and distinguished from most comparable language exams by testing five independent skills rather than the more common four — explicitly separating Analysis of Communication Structures, a dedicated grammatical-accuracy component, out from Listening, Reading, Writing, and Speaking. A candidate needs independent sufficiency in every one of those five components to receive the certificate, meaning a conversationally strong candidate can still fall short if their formal grammatical accuracy — assessed entirely on its own — doesn't separately clear the bar. Offered at fixed June and December sittings through Italian Cultural Institutes and accredited centres worldwide, CILS also provides purpose-specific variants, including a dedicated level built for Italian citizenship applications. Its main domestic alternative, PLIDA, serves a broadly similar general-certification role, so candidates should confirm which specific exam a target university, employer, or government authority actually names before committing preparation time to one over the other.