The English language has its challenges – even if it's your native tongue. Here's a short refresher course in “nym” words, “ nym” from the Greek onoma , meaning a name :

Acronym: a word formed from the initial letter or letters of a series of words such as NASA (National Aeronautics and Space Administration).

Antonym: a word opposite in meaning to another, e.g., fast and slow.

Autoantonym: a word that can take two (or more) opposite meanings; for example, fast means both moving quickly or fixed firmly in place.

Capitonym: a word that changes its meaning (and sometimes pronunciation) when it's capitalized: march and March.

Heteronym: words that have the same spelling, but different meaning and sometimes different pronunciation, such as lead (to conduct) and lead (a metal).

Homonym: words having the same sound and often the same spelling but different meanings: quail (to cower) and quail (a bird). Not to be confused with homophones, which are homonyms that have the same sound but different spelling and meaning (to, too, and two).

Metonym: a word that designates something by the name of something associated with it; e.g., the Crown referring to the monarchy .

When most people think of Valentine's Day, they probably aren't worried about appropriate etiquette for the office. But etiquette expert Lizzie Post of the Emily Post Institute says the subject deserves a little loving care. Her advice: Don't flaunt your plans – either before or after they've happened – when chatting with coworkers or friends.

In 1493, Christopher Columbus logged seeing three mermaids while he was sailing near the Dominican Republic . He wrote that he was surprised they weren't as attractive as the depictions he'd seen in paintings. So did the famous explorer actually see three half-fish, half-female creatures frolicking in the sea?

Not likely, experts say. Columbus ' mermaids were probably manatees, which can grow to lengths of up to 12 feet and weigh up to 1,200 pounds. Manatees look somewhat like aquatic elephants, and some think that the romantic depictions of mermaids with long green or blue hair might have been manatees breaking the water surface with seaweed hanging from their heads.