There is no “no as a separate phrase” in Gaelic – you can’t just say “no” on its own as that is not a word in this language.
When you give an answer to a yes/no question you always repeat the verb, and to give a negative answer you negate that verb.
Thus if someone asks you a bheil thu fuar? are you cold, you can answer either tha (I) am or chan eil (I) am not – and those are typically translated as yes and no respectively.
But if someone asked if an cluich thu iomain? will you play shinty? you will answer either cluichidh for yes, lit. will play, or cha chluich for no, lit. will not play.
But there’s no way to simply state “no” without any context, no word that could universally be used to translate English “no” or “yes”.