More Pesky Near Homonymns from the Harbace Glossary of Usage (usgl) (pp. G-1 through G-37 in the 12th edition)
An allusion is a casual or indirect reference. An illusion is a false idea or an unreal image: The allusion was to Shakespeare. His idea of college is an illusion.
Assure meant to "state with confidence." Ensure and insure are used interchangeably to mean "make certain." Insure has the further meaning of "to protect against loss." Marlon assured me that he would vote for my ticket. I insured (or ensured) that Vincent had his tickets before I left home. Betty insured her car against theft.
So how come there's the Bankers United Life Assurance Company, to name one of many insurance companies with "assurance" in their names? You can be assured that there's a good explanation.
Complement means "to complete" or "to supply needs." Compliment means "to express praise." Complimentary means "given free," as in complimentary tickets: Their personalities complement each other. Betsy complimented Jim on his performance.
Ingenius means "creative or shrewd." Ingenuous means "innocent or unworldly": Terry's ingenious plan worked without complication. The criminal's ingenuous smile was misleading.
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