Words easily confused: principal and principle.

I made a mistake with these two the other day, as my husband gleefully pointed out, telling me that:

Principal  is an adjective meaning ‘most important’ or ‘main’, or a noun designating ‘the main or chief one’. So, the main sum of money on which interest is calculated is called the principal, and the chief person or head teacher in a school is the principal.

Principle  can never be an adjective. It is a noun only, referring to a fundamental law or concept, or to a code of conduct, often used in the plural, as in ‘moral principles’.

• The principal objective is to make a profit.

• The former principal was dismissed because it was proved that he had embezzled school funds.

• Those are my principles. If you don’t like them, I have others.  (Groucho Marx quote)