principal principle

[Kingaroo]

Anyone have a good mnemonic? I know the difference, but a coworker keeps getting it wrong and I'd like to tactfully tell her "how I keep them straight."

We are talking about principal investigators and principal motives and such, not principals (headmasters) of schools, so I can't use the one I learned as a child, that the principal is your pal.

[Quizmonkey]

Not sure you need a mnemonic... Principal is the adjective meaning chief, key, main etc. Principle is the noun meaning a tenet, a belief you hold dear etc.

The only exception that you need to remember is the noun use of principal: as you say, the head of a school etc. But that's only spelled like that because he's the 'main man'.

[Marsh]

I don't know a traditional one but if you take the last letter, L is for leader and E is for ethics. Hope this helps.

[Celtigra3]

Principal - head - both a before the end

like stationary - think train

hope that helps! (a bit!)

[Xollob]

"The principal is your pal" is the mnemonic given on the site Common Errors in English.