Top 10 Commonly Confused Words, Vol. 1

Como em português às vezes confundimos, amostrar com mostrar, meio-dia e meio com meio-dia e meia, menos com menas etc. Dúvidas como essas também nos aterrorizam em Inglês. Encontrei uma lista de 10 pares de palavras que são "confundíveis". Veja abaixo qual o uso correto para determinada situação:

#1: Flaunt/Flout

Question: If you treat convention with disdain, are you flouting or flaunting the rules?

Answer: flouting

How to Remember It:

Think of whistling – or actually, playing the flute – instead of doing what's expected.
Why? Because flout probably originates in the Middle English word flouten, "to play the flute." It's not clear how a word for playing the flute evolved into a synonym of mock and insult (the original meaning of flout), but here's a guess: in the hands of some entertainers, the flute can project a teasing, even mocking, carefree air.
By the way, using flaunt in sentences like the one above is now standard, although many folks still consider it incorrect.

#2: Affect/Effect

Question: Does the weather affect or effect your mood?

Answer: affect

How to Remember It:

The simplest distinction is that affect is almost always a verb, and effect is usually a noun.
It may help to remember that the verb – the "action word" – starts with "a": affect is an action.
These words are frequently confused, partly because their meanings are related.

#3: Desert/Dessert

Question: If you receive an appropriate punishment, did you get your just deserts or just desserts?

Answer: just deserts

How to Remember It:

This word is unrelated to deserts of the sand and cactus kind, and it isn't about the desserts that provide a sweet finish to a meal.
Instead, this deserts comes from the same word that gave us deserve. (Oddly, it's pronounced like desserts.)

#4: Stationary/Stationery

Question: Do you buy your writing paper in a store that sells stationary or stationery?

Answer: stationery

How to Remember It:

For one, consider the histories of these words.
Stationery comes from stationer, a word that in the 14th century referred to someone who sold books and papers. What the stationer sold eventually came to be referred to by the noun stationery ("materials for writing or typing" and "letter paper usually accompanied with matching envelopes").
Meanwhile, the adjective stationary has always been used to describe what is fixed, immobile, or static.
Here's another way to remember it: stationery is spelled with an "e," like the envelopes that often come with it.

#5: Flak/Flack

Question: If you're getting shot at by antiaircraft guns, or receiving unfriendly criticism, are you taking flak or flack?

Answer: flak

How to Remember It:

Although flack is an established variant, the more foreign-looking flak is the original spelling and the better choice. Flak was originally a German acronym for Fliegerabwehrkanonen – from FLieger ("flyer") + Abwehr ("defense") + Kanonen ("cannons") – which basically means "antiaircraft gun."
That use of flak in English dates back to 1938. In the decades after the war it took on its civilian meaning of "criticism."
(A flack, meanwhile, is a PR agent or someone who provides publicity.)

#6: It's/Its

Question: The car won't start because its battery, or it's battery, is dead?

Answer: its

How to Remember It:

The word it's means "it is" or "it has," while its means "belonging to it."
In the sentence above, "it is battery" or "it has battery" doesn't work – so the correct version has to be its.
Similarly, in the sign shown here, "it is/has accessories" and "it is/has enclosure" don't make sense, so it's wasn't the right choice.

#7: Pore/Pour

Question: When you're attentively studying, are you poring over or pouring over the materials?

Answer: poring

How to Remember It:

One reason this word trips us up is that both pour and pore are often followed by over.
But in this case it probably helps to think literally. When we're intently studying something, nothing is actually pouring (i.e., flowing, leaking) onto the object of study; in fact, if something did pour onto what you're poring over, your task would be far more difficult. The less familiar verb pore is correct.
(Pore actually has the same root as pour, but of course that only adds to the confusion.)

#8: Fewer/Less

Question: Does the average American family have less than two kids or fewer than two kids?

Answer: fewer

How to Remember It:

Fewer refers to things that can be counted (fewer kids, fewer chairs). Less usually refers to quantities of things that can't be counted (less coffee, less agitation).
However, under certain circumstances less, not fewer, is more commonly used with countable things. For example: Less than twenty miles, less than five dollars, and 1500 words or less, are considered standard.
As for the express lane at the supermarket, "ten items or fewer" follows the general rule, but "ten items or less" is also widely accepted and more often used.

#9: Flounder/Founder

Question: If your ship fills with water and sinks, does it flounder or founder?

Answer: founder

How to remember it:

When something founders, it loses its foundation. (Founder and foundation have the same root.)
To founder is to collapse, sink, or fail.
One source of confusion here is that the meaning of the verb flounder is similar: to flounder is to struggle to move or get one's footing, or to proceed or act clumsily or ineffectually. People can flounder, but ships founder.

#10: Principal/Principle

Question: Is the person in charge of a school the principal or the principle?

Answer: principal

How to remember it:

A couple of mnemonics based on letters are useful here: the principal is your pal. Principle, like rule, ends in "l-e."

Fonte: http://www.merriam-webster.com/