I have been writing high school English paper on a novel in MLA format. Is there any rule about using past participle or past imperfect? Throughout the essay there have been many places that can be changed from past to present, but there are some areas where there seems to be no way to changed to present. This has gone unchanged in revisions by other, meanwhile other verbs have been changed by other people to present tense.
after forty years pass.
This was corrected by a writing teacher (not my own) to "passed". I am wondering if this is correct, and if there are any exceptions to the rule that past tense cannot be used in MLA formatted essays.