Believe it or not, it could be either one. The "if only..." construction is often used to express regret about something that is not true, as a stand-alone comment and not a fragment. It often has an exclamation mark. If only

It's usually used with an exclamation mark: ! It means...this/that is a good deal. Personally, I would like this construction to fall into complete disuse in English.

I believe that the ghost that has appeared before me truly is my father’s spirit, and that everything it has said is true. The ghost did not flee before Horatio’s “cross,” and it shows Christian forbearance towards my “common” mother. Thus, I

Was that easy! and Am I hungry! are particularly American constructions. I don't think we have this inversion for an exclamation in BrE. When we use the negative, it's formally an interrogative, so if I say Isn't he clever? it's like asking Don't