I would say that the difference in meaning between these two sentences is slight:
1. “I hope you will change your mind.”
2. “I hope you change your mind.”
We must keep in mind that both are elliptical constructions of the sentence “I hope
that you will change your mind.” That sentence is, of course, a complex sentence consisting of the main clause “I hope” in the present tense and the subordinate relative clause “that you will change your mind” in the future tense.
In Sentence #1 above, only the relative pronoun “that” is ellipted or dropped, while in Sentence #2, both “that” and the auxiliary verb “will” are ellipted from the relative clause. (Click this link for my earlier Forum posting on
"Deconstructing and understanding those puzzling elliptical sentences.") Both ways, the meaning of the original sentence isn’t significantly altered.
The slight perceivable difference between the two sentences is that in Sentence #1, the speaker hopes that the person being addressed will have a change of mind sometime in the indeterminate future, while in Sentence #2, the speaker hopes that the person being addressed will have a change of mind right away or not long after the hope is expressed.
As to your second question, the verb phrase “file an annulment” is grammatically erroneous; the form is “file for an annulment” is grammatically correct, but the idiomatic usage is “file for annulment,” with the article “an” routinely dropped, as in this sentence: “The irate wife
filed for annulment of her marriage to her philandering husband.”
