नाही(nAhI) and नको (nako) are two words used in Marathi in negative sentences. In English, equivalent to both of these is “No”/”Not”. It confuses learner which is used when. But careful observation of previous grammar lessons will show that नको (nako) is used only in particular cases and in all remaining sentences it is नाही(nAhI)
नको is used in negative forms of imperative sentences i.e. requests, suggestions, advice, or commands.