'Principal' or 'Principle'? What Is the Difference? | Mastering Grammar

(Last Updated: 17 March 2023)

The Difference between Principal and Principle

It is easy to confuse principal with principle because they are homophones (both are pronounced /ˈprɪnsəpl/ or /ˈprɪnsɪpl/). Homophones are words that sound the same but are spelt differently.

Principal can be either an adjective or a noun.

As an adjective, it means 'main' or 'most important':

✅ Teaching is my principal source of income.

✅ The principal reason for going to Japan is for the food.

As a noun, it means 'the person in charge of a school or college':

✅ Who is the principal of King's College?

✅ The principal has approved our proposal.

Principle is a noun meaning 'a basic rule' or 'a belief about what is right or wrong':

✅ We learnt the basic principles of car maintenance.

✅ Lying is against my principles.

Tips for Remembering the Difference between Principal and Principle

The first mnemonic above serves to remind you that principal may be an actual person, who may be your friend. Use the same word as a describing word to mean something like 'main' or 'chief'.

Examples from the Media

White House officials say they have no evidence to suggest anything nefarious or criminal is in the works, and that their principal focus for now is clearing the border blockades. —Toronto Star (2022)

Principals in Virginia's Loudoun County Public School District, near Washington D.C., have been given a step-by-step guide to help them apply for a warrant from a magistrate should any student try to enter school without wearing a mask. —Daily Mail (2022)

A national campaign should be launched to educate people in the basic principles of parenting, a government-commissioned review concludes today. —The Guardian (2011)

To help Hong Kong's younger generation develop strong moral principles, RTHK has produced a TV series called Ethics Education which is intended to be educational as well as entertaining. —South China Morning Post (1996)

Real-World Examples of Misuse

Image Source: HKDSE英國語文科作文升星秘笈

1. The plus sign is not required because the writer has made it clear that she has worked 'for over' ten years.
2. Principal and principle sound the same, but their meanings are vastly different. A principal is someone who is in charge of a school or education centre. A principle refers to a rule or guideline.
3. The capitalisation is not required as the writer is referring to education centres in general terms and not stating their official names.
4. The capitalisation is not required as the writer is referring to a phonics programme in general terms and not stating the official title.
5. Alternatively, you could say 'makes learning fun'. This is perhaps more accurate as the participants are not learning the programme itself.
6. Using the pronoun them here avoids the repetition of 'sounds'.
7. The singular form (kid or child) should be used. If a course or programme is child-friendly, it is designed with the needs, interests, or safety of children in mind.