Principal or Principle?

Writers occasionally confuse the words principal and principle.

Principal

In its most common role, principal is an adjective meaning main or key. Examples:

• The principal objective is to make a profit.

• (The adjective principal modifies the noun objective.) (principal = main or key)

• The inspector highlighted my principal concern in his opening sentence.

• (principal = main or key)

The word principal can also be a noun meaning 'head or chief'. It is commonly used to denote a head teacher in the US.

• Here comes the principal.

• (principal = head teacher)

Principle

The word principle is a noun. It has a range of meanings, including rule, belief, tenet and theory. In general, principle offers the idea of general law or code of conduct.

• No! It is against my principles!

• That is a great idea in principle.

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

• You could strengthen your argument by appealing to more general principles.