Affect vs. Effect
Watch out, folks. Affect and effect represent one of the trickiest dynamic duos you'll find in the grammar world.
A general rule of thumb is if the word has an article (a, an, the) in front of it, it should probably be effect. If it's used as a verb, it should probably be affect.
We repeat, probably.
As a verb, the word affect means to influence in some way. As a noun, it refers to a person's feelings and emotions and how they are displayed.
Examples using Affect:
"If I were in a position to affect real change in this world, I would start by instituting mandatory naptime for people of all ages."
Who ever said you stop getting tired in the middle of the day after kindergarten? In this sleepy sentence, affect is a verb that means the same as influence.
"Recalling my girlfriend's affect over the past two weeks, I think our "talk" this afternoon is going to be more like a train wreck."
It's not him, it's her. Here, affect is used as a noun that refers to the girlfriend's feelings.
The word effect is mostly used as a noun and refers to something caused by something else: hence the common phrase "cause and effect." Though rarely used as a verb, effect can also mean to achieve a certain result.
Example using Effect:
"Until Duke tried the Thai drunken noodles at SriPraPhai, he thought that spicy food had no effect on his digestion."
We already feel bad for Duke's roommates. In this sentence, effect is a noun that refers to digestive issues caused by the offending noodles. Stick with the Pad Thai next time, Duke.