1
                           general:: 
                            Phrase(s): I doubt that. 
I do not believe that something is so.  •  Bob: I’ll be there exactly on time. Sue: I doubt that.  •  John: Fred says he can’t come to work because he’s sick. Jane: I doubt that.
                        
                        
 
                        
                            McGrawhill's American Idioms And Phrasal Verbs