Ma'anar ƙamus na kalmar "biyu korau" gini ne na nahawu wanda ke amfani da kalmomi biyu marasa kyau ko barbashi don bayyana kore ɗaya. A daidaitaccen nahawun Ingilishi, mara kyau biyu yana haifar da tabbataccen magana. Misali, jumlar “Bani da kowa” tana amfani da korau biyu saboda “ba” da “babu” duka kalmomi mara kyau ne. Madaidaicin sigar wannan jimla zai kasance "Ba ni da ko ɗaya," wanda shine mara kyau guda ɗaya kuma yana bayyana mummunan magana. A wasu yarukan da maganganun da ba na yau da kullun ba, duk da haka, ana iya amfani da ɓangarorin biyu don jaddada magana mara kyau, amma ana ɗaukar wannan amfani ba daidai ba a rubutu da magana.