"I never say no."
Translation:Yo nunca digo que no.
Googling both phrases I get similar ball park of hits. One purpose of "que" is as a conjunction and conjunction are not always needed in English and that may apply to some Spanish situation too. I think of "que" here as setting up dialog tags. "Yo nunca digo que no." = 'I never say, "no"'. Maybe when "que" is setting up a quote it is optional in Spanish?