Generally speaking, no.
When you turn in an assignment for a class, you’re not just claiming that the work is original to you, but that it is also new.
While this can sometimes feel like needless and pointless work, it’s important to remember that an assignment aims to gauge your skills and understanding now, not where you were weeks, months or years ago. It’s also to help you learn more about the subject so finding new ways to write or think about a topic can be very helpful in understanding it.
Reusing your previous work can be especially problematic if your school uses any kind of plagiarism detection software. If you submit content you’ve turned in elsewhere (or even posted online previously) it will likely come back as matching and it may trigger an investigation.
That being said, there are times where reusing past work may be appropriate.
For example, if you’re doing intense research into a subject as part of your studies, you may wish to reuse text or findings from you previous papers on new ones.
In those situations, the best thing you can do is speak with your instructor and explain the situation. If you are transparent about your desire to reuse previous work and why you think it’s the best solution, there’s at least a decent chance your instructor will allow it.
When speaking with your instructor, be sure to outline why you feel it’s appropriate to reuse your own work and, most importantly, how you’ll be expanding upon the idea.
Simply reusing an old paper isn’t showing any new progress. Even if it fits the assignment, there are almost certainly ways you can write it better/clearer, expand upon the idea or bring in some new research.
Still, in doing that, you may wish to use parts of your previous work and your instructor can help guide you on what is and is not acceptable for that.
It’s important to remember that you still need to cite your original work, just as you would any other outside material. This transparency helps your readers understand how you have developed your ideas and how your previous work connects to your current writing.
While it might seem crazy to cite yourself, it’s something researchers do all of the time. For example, when a researcher is working in a narrow field, they may do many similar experiments to test how changing small variables alters the outcome.
They may reuse portions of their previous text but cite their work to indicate where they are getting their previous information, whether it’s the setup for the experiment or the results.
In short, when it comes to reusing your work in the classroom, the answer is “Generally No” not “Never”. There are situations where it can be appropriate but only if it’s done with complete transparency.
After all, plagiarism isn’t just about stealing works from others, it’s about giving credit where credit is due: Even if that means to giving it to your past self.