A principle is a rule, belief, or basic idea. Principal can mean main, a school leader, or the amount owed on a loan apart from interest. You can use both spellings in one sentence about a school policy.
Compare the rule, the leader, and the main reason
- “Fair access is one of our guiding principles.” The word names a belief that shapes decisions.
- “The principal announced the new schedule.” The word names a person who leads the school.
- “The principal reason for the change was safety.” Here it means main.
Check the role of principal on a loan statement
A payment can reduce the principal balance, the amount still owed apart from interest. For the adjective meaning main, always use principal. For a belief or rule, use the noun principle. Merriam-Webster’s usage note.
Try it
“The school ___ explained the ___ behind the rule.”
Show the answer
Use principal for the school leader and principle for the idea behind the rule.
See also Capital vs. Capitol.
