Here are two words that often get used incorrectly: “principal” and “principle.”
“Principal” means the most important person or thing. It can be a noun (e.g., the principal of the school) or an adjective (e.g., the principal issue).
“Principle” is a noun that means a fundamental law or doctrine. (e.g., “It’s the principle of the thing.”)
How can you remember this? Two ways.
First, the principal – the “main” person at school – was supposed to be your friend or “pal.” (Whether or not that was the case is another matter.) So use the “pal” ending whenever referring to the “main” person or thing.
Also, note that “principle” is only a noun. It is not an adjective. (“Principled” can be used as an adjective, but seldom is.) So if you want to modify a noun, use “principal.”
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