Harbrace 18b: Distinguish between words of similar sound; use the spelling required by the meaning.
Section 18b includes nice list of the Top 100 sets of Words Whose Spellings Are Frequently Confused. It also refers us to the excellent Glossary of Usage in the back (pages G-1 through G-11 marked usgl in the upper right corner).
But here are four particularly pesky homonym/homophones:
Right: "The Dow Jones Industrial Average peaked at 12,500."
Right: "The story piqued my interest."
The word pique comes from the French word piquer, to prick. Pique has several meanings: 1) to arouse anger or resentment in, or offend by slighting, 2) to excite or arouse by provocation, 3) to stir up the pride in an accomplishment.
Other homonyms (or near homonyms) that trip almost everyone up:
"I am the Marquis de Sade." (a nobleman below a duke and above an earl)
"The theater marquee said the show started at 7:00 pm." (a permanent canopy projecting over an entrance to a theater or a hotel)
"Because of the court's ruling, the lawyer's point is rendered moot." (deprived of practical significance; a great Old English word)
"After his traumas in the holocaust, the young Jerzy Kozinzki was rendered mute." (unable to speak)
"The speech was filled with wonderful anecdotes." (short, amusing stories or biographical incidents)
"After he was bitten by the snake, the adventurer called out for the antidote." (a remedy to counteract the effects of a poison)
"Ronald Reagan charmed the nation with his self-deprecating humor." (effacing; expressing mild or regretful disapproval)
"The house had somehow depreciated over the past decade." (decreased in value)