有乜adjective是ly尾，有乜noun 又是 plural 又可以是singular

又係singular 又係plural 既 noun: sheep, fish, headquarters, means, species, series, crossroads

其實staff, audience, public 等並唔係singular / plural, 而係collection noun(集合名詞), 即係果個字指一個集體, 例如staff係'一群職員', 如果想指'一個職員, 就要講'a staff member'

ly尾adjective: daily, early, elderly, friendly, likely, lovely, costly, holy, lively, lonely, monthly, silly, ugly, weekly, yearly, curly, deadly, chilly, cowardly, oily, smelly, sly, timely