Sound-alike words

Principal vs. Principle

Principal means main or most important, and it is also the head of a school or a sum of money. Principle is always a noun: a basic truth, rule or belief. The principal reason she quit was a matter of principle.

Word	Part of speech	Meaning
principal	adjective	first in importance; main or most important
principal	noun	the head of a school, or the original amount of a loan or investment before interest
principle	noun	a basic truth, rule or belief that guides how someone acts or explains how something works

Principal

adjective: first in importance; main or most important

The principal ingredient in this soup is roasted squash.
Cost was the principal reason we chose the smaller apartment.

noun: the head of a school, or the original amount of a loan or investment before interest

The principal greeted every student at the door on the first day.
Each monthly payment lowers the principal on our car loan.

Principle

noun: a basic truth, rule or belief that guides how someone acts or explains how something works

She refuses to cheat at cards, even for fun, on principle.
This week the class is studying the principles of simple machines.

How to remember the difference

The principal of your school is your pal. A principle is a rule, and principle and rule both end in -le.

Good to know

Principal is also a noun in business and law for a main person in a deal, as in the principals in a contract. Principle is never an adjective, so the principle reason is always a mistake.

Spot the mistake

The ~~principle~~ principal cause of the delay was a broken signal.
Correct: The principal cause of the delay was a broken signal.
He returned the extra change as a matter of ~~principal.~~ principle.
Correct: He returned the extra change as a matter of principle.

Check yourself

Pick the word that fits each sentence.

1. Our announced that school will close early on Friday.

2. Honesty is a I try to live by every day.