You must maintain a consistent verb tense.
I have got into numerous arguments with novice authors on this one. It is a bone of contention for me because, frankly, we don't ever speak in one consistent tense so why should a story be told in one? Not to mention that if the story is to have any three dimensional time continuity, it can't really be in just one tense anyway.
Mostly new authors are told to pick either past or present and to stay within the tense ranges for those two, but in actuality there are at least thirty of them, tenses that is, and it's good to know the basic six and how to move between them. Purdue University has an easy to understand guide for when you are trying to figure out when and how to shift tense. For example:
Did you notice the shift? The majority of the book is told in past tense and its variables, but as the narrator is reminiscing over what is to be a quintessential moment in her life, she switches to present tense to give the scene the immediacy it needs for impact. After the scene is over, the narrative resumes in past tense. This happens often throughout the book.
"He shimmered in the mirrors. An infinite number of Adrians in beige corduroy trousers and plum colored turtlenecks and brown suede jackets. And infinite number of dirty toenails in an infinite number of Indian sandals. An infinite number of meerschaum pipes between his beautiful curling lips. My zipless fuck? The man under my bed! Multiplied like lovers in the last year at Marienbad. Multipled like Andy Warhol’s self-portraits. Multiplied like the One Thousand and One Buddahs at the Temple of Kyoto. […]
“Hello Ducks,” he says, turning to me.
“I have something for you,” I say handing him the inscribed book I’ve been carrying around all day. The edges of the pages are beginning to fray from my sweaty palms.
“You sweetheart!” He takes the book. We link arms and start walking down the mirrored hall.
From Fear of Flying by Erica Jong.
So you tell me -- six point something million copies sold. Award winning author Erica Jong -- did she and/or her editor make a serious mistake? I think not.
So this is just another one of those rules that has been distorted over time by people who don't understand it yet feel the need to shove it down everyone else's throat. No wonder so many new authors get confused. Feel free to shift tense when appropriate for effect, but make sure you do it right and do it subtly. An author shouldn’t have a fear of flying.
On a side note: I am embarrassed to admit that I am just getting around to reading Fear of Flying. I know, I know, in '73 when it came out, it was lauded as one of the greatest works of literature of all time, and it is. It was one of the first books to explore the feminist psyche in such an unapologetic way, and one of the first to do so written in the style of a memoir. However, I wouldn't have really been able to relate to it as deeply in my Twenties, but now that I am well into my Forties and have one divorce and a second marriage under my belt, I can appreciate the psychological truisms that would have eluded me as a younger reader less experienced in the ways of love, sex, and relationships. The book is witty, shocking in its exhibitionism, but most of all, it's honest. I don't know of any woman who hasn't thought or felt this way at some point in their life about the men in their life and how it all relates to their own sexuality. As a bonus, the writing is stellar.
Cheryl Anne Gardner