I was reading some vintage Orwell and I came across " ... oughtn't to say ... .". This sounded reasonably archaic or foreign to me. Then I realized that my ideolect dictates that "ought not" ought not be followed by "to." Even I recognize that it's odd. Still, there is no question about it that two distinct rules are at play.
Looking up usage, it appears to vary regionally in the US. I can't recall ever hearing "ought not to" or "oughtn't to" anywhere in my US travels.
So, where are you from? And what do you hear and say?
Where I'm from (northern California), I usually heard ought not. My grandmother, from Massachusetts, would say ought not to or oughtn't to. But everyone knows that Easterners talk funny.
Thanks for the data points.
I had a great aunt who used to say durst and durstn't (/dersint/) but I haven't heard those in decades.
My grandmother (also from Massachusetts) used to say "oughtn' not", usually talking about something I have done already, but should not have.