Affect and Effect are two English words with fairly similar meanings, and fairly similar pronunciations as well. Yet although they are not true homophones (words which sound alike), there is enough similarity in them to cause a lot of people a bit of confusion. Even folks who use them frequently will very often find themselves stumped over which word is the correct one to use.

The word affect is almost always used as a verb in English. It means to change or alter something. Her death affected the survivors in a profound way. How will my vote affect the outcome of an election?
But the word effect is most often used as a noun in English, and is characterized by something that is produced by an agent or cause. The result or consequence directly related to a sort of catalyst. The effects of her death left the survivors in a daze of disbelief. Cause and effect are necessary to formulate a scientific theory.
Easiest to remember: A for action word -- A for affect. It makes a good effect, overall.
But the word effect is most often used as a noun in English, and is characterized by something that is produced by an agent or cause. The result or consequence directly related to a sort of catalyst. The effects of her death left the survivors in a daze of disbelief. Cause and effect are necessary to formulate a scientific theory.
Affect may rarely be used as a noun, but its usage is nearly obsolete and a bit pointless to dredge up out of archaic retirement.
Effect also, may occasionally be used as a verb, and is a wee bit more common than the noun uses of affect, but probably best to simply steer clear of adding more yarn to an already tangled web.
Easiest to remember: A for action word -- A for affect. It makes a good effect, overall.
