The school principal’s principal principle is to pay off the principal.

“Huh?” you might be thinking. But yes, the above sentence is grammatically correct. You can easily decipher this and use the words “principal” and “principle” correctly by simply reviewing some definitions: 

Let’s start with principal. We’ve all dreaded this word at one point or another as children, but there’s more to it! Here are its three definitions:


  1. first in order of importance; main. Example: The principal purpose in having a ratio of three patients to one nurse is to provide optimal care.
  2. (of money) denoting an original sum invested or lent. Example: I plan on making additional principal payments on my mortgage if I can ever pay off my Bugatti car loan.*

*Principal can also be a noun when referring to money. Example: Congrats! You paid off the principal of your mortgage!



  1. the person with the highest authority or most important position in an organization, institution, or group. Example: Ferris Bueller, you are wanted in the principal’s office … now!


Moving on to principle, which has two definitions that are similar.


  1. a fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning. Example: There are several principles of health care ethics that are designed to improve patient care.


  1. a general scientific theorem or law that has numerous special applications across a wide field. Example: The principle of energy makes it clear that the light emitted laterally is not a new creation, but only diverted from the main stream.

Now try to apply those definitions to our original sentence. 

—Sarah Muench