Because I’m teaching a technical communication course on writing and editing this quarter at MSOE, I’ve had issues of grammar, punctuation, and spelling on my mind more than usual lately.  One common error that came up in class last week was “principle” versus “principal.” 

Everyone probably knows that a principal is your “pal,” but how do you remember which spelling to use in in contexts not involving school administrators?

Here’s my trick.

• “Principle” with “le” = a rule.  Both words end in “le.”
• “Principal” with “pal,” or, more precisely, with “a” = the main something.  Both words have an “a.”

So we would talk about:

• the principles of physics (the rules of physics)
• the principle of a thing (the rule that is supposed to be followed)
• a principled person (a person who lives by a strong moral “code,” or rule)
• a matter of principle (an expression usually associated with an issue defined by values, morals, expectations, or the rules associated with the situational context)

Or we would talk about:

• the principal of a school (the main teacher/administrator)
• the principal point of a discussion (the main point)
• principal and interest (the main sum of money you have sitting in a bank, which earns interest)
• the principal of a company (main/key person in charge, often the owner)

Principle = rule.  Principal = main.

I’m very sold on mnemonic devices as strategies for learning, retaining, and recalling complex information.  Using the “le”/“a” mnemonic to remember the correct spellings for “principle” and “principal” has always worked well for me.  Maybe it can for you, too.