My GMAT book, GMAT Ultimate Grammar, has different sentence structures for present subjunctive form and present contrary to fact form. However, they both seem identical to me because in the examples given of each form, they both talk about something that isn't true. The book gives an example of each:
- Subjunctive: She would rather that the plane leave early in the morning.
- Contrary to fact: Debby would rather that her boyfriend spent Friday nights with her.
After stating the contrary to fact example, the book says that the sentence implies that Debby's boyfriend does not spend Fridays with her. However, couldn't you argue that their example for the subjunctive case implies that the plane will not leave early, making it contrary to fact?