Principle vs. Principal

Principle and principal are pronounced identically, so how do you know which one somebody is talking about? And how do you know if you are using the word that you are intending to when you are writing? Let’s take a look at the differences and similarities between principle vs principal!

Principle vs Principal as Nouns

Principle – a fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning.

Principal – the person with the highest authority or most important position in an organization, institution, or group.

These definitions of principle and principal are from, and the noun form of each was used. We will look more closely at the other forms of the words later.

So, as you can see from these definitions, the two words have very different meanings, even though they sound the same. So it’s essential that you know how to decipher between the two.

Misusing the words in an important document can appear unprofessional and can encourage people to disregard anything else you have to say.

Principle vs Principal Other Differences

Principle is always a noun.

Principal can be a noun or an adjective.

Principal as an adjective: first or highest in rank, importance, value, etc.; chief; foremost.

To help with the overall understanding of the differences between the two words and how to use them, we will take a look at an example of each.

The business’ principles were put in place to ensure customer satisfaction.

The principal of the school was in charge of interviewing the new applicants.

The principal goal is to find a long-term solution to this widespread issue.

Some people may confuse the adjective form of principal with the noun principle, because they both show a level of importance, by their meanings.

While this is true, they cannot be used interchangeably, just as principle and principal cannot be used interchangeably in any situation.

Here is a quick tip for properly using the words as adjectives. Principal does have an a in it, while principle does not.

We can use that a in principal to signify that principal may be used as an adjective.

Principle is missing the a, so it cannot be used as an adjective.

This, of course, is not true in every case when using all words as adjectives. But in this particular case, it can be helpful.

Principle vs Principal History and Latin Roots

Principle has a Middle French history. This word has evolved from the word principe, which is from the Latin word principium. Its meaning is “source.”

Principalis is the root of principal, meaning “first.”

Both principal and principle have Latin roots. Princip or princeps is defined as “first” and in some cases “chief.”

Principle vs Principal Remembering the Differences

Principle vs. Principal - Memorization tricks

For the noun forms of principle vs principal:

Just remember, pals are people, so a princiPAL is a person. And a principLE is a ruLE you follow.

Note that the passage does not help in the case of principal as an adjective.

To remember that only principal can be an adjective:

Remember that principal has an “a” like adjective. Principle does not have an “a, ” and it can’t be used as an adjective.

Practice makes perfect.

It might also be helpful to practice using principle and principal in your everyday speaking or writing.

It will be especially useful if you are able to have access to references when you are using the words so that you can check yourself. This is definitely an excellent way to prevent misusing a word on an important document and sending it without double-checking.

If you misuse the word when you are writing on your personal blog or speaking to a friend, there are little risks in those types of situations. More importantly, they are an excellent opportunity for you to go back and read some material on the differences or take another look at the definitions to help you out. We sometimes learn best when we make mistakes! Self-correction is especially beneficial to success as well!

Using in principle

Let’s take a look at another use of the word principle. The phrase in principle will naturally be misused and could be misinterpreted as well, due to the confusion between principle and principal.

The dictionary’s usage of in principle is “in essence or substance; fundamentally.”

One example of in principle being appropriately used is when two or more individuals or groups are agreeing to something based solely on the fundamentals. In principle would not be accurately used when looking into the details of the agreement.

It would be wise to agree to a contract in principle if you understand the basics. Then you would take some time to look over the rest of it as a whole and in more depth before agreeing completely. It’s important to look at something in principle and then to thoroughly analyze the other features as well.

Perhaps two companies operate similarly. Maybe they sell the same type of items or offer competing services that look a lot alike. They are the same in principle, but other things distinguish between the two. The differences may not be apparent until someone chooses to dig a little bit deeper and investigate the companies.

Using on principle

Another way to use the word principle is on principle.

According to the dictionary, on principle can be used “according to personal rules for right conduct; as a matter of moral principle” or “according to a fixed rule, method, or practice.”

We can think of this in terms of a nurse who always washes his or her hands before entering a patient’s room in the hospital. This is their practice, and it is a routine to that nurse. We can probably all say that we would want our medical providers to wash their hands that often, and most of them do, on principle.

Similarly, we could consider how someone may choose to avoid a situation because they don’t agree with it morally. The person is deciding, on principle, that they don’t want to get involved, because it may contradict their personal values. They are making a choice based on their principles or on principle.

Examples of Principle and Principal

Because it’s so beneficial for us to use the words principle and principal correctly, we should get some practice with them.

It may be helpful for you to read through these sentences and have some dialogue with yourself about why the specific usages of principle or principal are being included. Challenge yourself to learn the differences and to recognize them in writing.


My parents’ principles align with my grandparents’ values and beliefs.

I agree with my company’s revised principles because the previous version did not benefit everyone involved.

Though I agree with the plan in principle, I want to read it in detail before committing to it.

That business’ principles are focused on customer satisfaction.


She chose the job based on her principal goal of promotional opportunities.

After Mr. Davis was the principal of our school for 10 years, he went on to be the superintendent of the district.

The principal objective of the lesson was the difference between the types of literature.

That bank requires a principal balance of $100 in each new account opened.

In conclusion

It is necessary to know the differences between principle and principal, as their meanings are quite different. It is also crucial that you are able to decipher between the parts of speech in relation to these particular words so that you do not end up more mixed up than you were before.

Try to use some type of memory trick, to help you memorize the difference between principle and principal. Another idea is to consider the different contexts where you will be using each word. When you are writing or speaking, think about what point you are trying to convey. Then reference the definitions if you can, as suggested above.

Reflection is a vital part of the learning process because it allows us to take another look at our work and understand the changes that we need to make. When writing or talking, take a minute to reflect on why you used the word principal or principle and why it is correct. Again, this will give you a greater understanding of the meanings and contexts in which to utilize each of the words. This method will provide you with a useful and applicable way to grasp the concept.


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