Affect and effect are often used incorrectly, particularly in student essays. In most contexts, affect is a verb and effect is a noun. When you affect something, it produces an effect – and I think that is where some of the confusion stems from.
Affect
Affect as a verb means ‘to influence or change’ or ‘to make a difference to’, and it is the most common use of affect.
The new rules will affect thousands of people.
It can sometimes mean ‘to pretend’ or ‘to take on or adopt something pretentiously’.
I affected a happy disposition. He was known to affect an American accent.
It has limited usage (usually related to psychology) as noun referring to an emotion or feeling.
His reaction displayed a happy affect.
Effect
Effect as a verb means ‘to do’ or ‘to bring about’.
I will effect change.
But the most common usage of effect is as a noun meaning ‘a result’.
It had an immediate effect.
The a, an or the test
If you struggle to work out which word you need to use, this simple test might help. Does a, an or the appear in front of it? Or if you inserted a, an or the would the sentence make sense?
The effect was insignificant. It couldanaffect your lifestyle.
If the answer is yes, you probably need effect (the noun). If the answer is no, you probably need affect (the verb).
Hannah McCall 
Its just so easy to mix up some words at times! I distinctly remember the nights when I had to think hard before I chose which one to use, “Affect” or “effect” because I am just so tired my mind can’t process things anymore! lol it’s fun though.
Loved your site. It has got lots of fun words and explanations.
Keep it up.
Have a wonderful weekend.
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Yes, it is very easily done!
Thank you for your kind words about my blog – I’m glad you liked it.
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Hannah, I noticed you followed my Psyched to Write blog. Thanks for the follow, but I haven’t posted to that blog in years. I use http://www.marshaposz.wordpress.com, my Dogwood Daydreams blog. Sorry for the confusion!
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Ah, I see. Thanks, I have now followed the correct blog!
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Thanks for the “likes” on two of my posts! Great grammar/usage lesson. My students are always stumped by this one. Please feel free to visit my blog again sometime.
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No problem. Thanks. 🙂
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[…] ‘Affect’ and effect’. I mostly like this because the comments took me from Pirates of the Caribbean to Pokémon. […]
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Awesome–never know about the a, the, and an test. Nice trick–thanks for sharing. 🙂
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No problem. 🙂
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Reblogged this on Don Massenzio's Blog and commented:
Here are some important rules that may affect the effects within your writing. Enjoy.
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This is one I see a lot in the gaming industry because both terms are frequently used to describe elements of a game. For example, “The magic missile spell is a force EFFECT that can AFFECT incorporeal creatures.” That example is a bit of an exaggeration, but not by much.
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Yep, that sort of thing is very familiar! (And has made me want to dig out a Pokémon game immediately.)
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Thanks for the useful tip. I appreciate it.
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I’m glad you found it useful. 🙂
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Very useful – thx 🙂
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Thanks. No problem. 🙂
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“It has limited usage (usually related to psychology) as noun referring to an emotion or feeling.”
Or, if you’re Johnny Depp, a tricorn, a musket and/or a cutlass.
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“Commodore Norrington, my effects, please. And my hat.”
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Really? I always interpreted it the other way… An abbreviated reference to his various, decorative affectations.
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Well, effects is the term for personal belongings. But that is an interesting way to interpret it – it would certainly fit the character.
I really want to watch the film now …
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