The suffix 性 turns adjectives into abstract nouns, like English '-ness' or '-ity': 积极性 (positivity), 重要性 (importance), 可能性 (possibility), 创造性 (creativity).
usage
Common collocations: 提高积极性 (boost enthusiasm), 调动积极性 (mobilize initiative), 打击积极性 (dampen enthusiasm). The word often appears in work and education contexts.
