For most people, it is difficult to know when and how to use "affect" and "effect." The confusion primarily comes from two things: (1) the two words are very similar in both spelling and pronunciation and (2) their meanings have evolved through the years, making it difficult for us to understand how the two words should be used today. But their meanings and uses have stabilized in recent years, so let's sort this all out. It's really not all that difficult.
In years past, "affect" was used as either a noun or a verb, but now its use as a noun is considered obsolete. Except in rare cases of some psychological studies, "affect" is now considered only a verb -- that is, a word of action.
"Effect," on the other hand, can be used as either a noun or a verb.
"Affect" as a verb and "Effect" as a noun
"Affect" as a verb implies the thought, action, impetus, or stimulus that produces a response or reaction. The actual response or reaction -- a noun -- is called the "effect." In remembering how these two words are used, take note that in the alphabet "a" comes before "e." Hence, "affect" comes before "effect." In other words, the "affect" can be considered as the driving force, stimulus, or influence resulting in the "effect."
Here are some examples of correct usages of affect.
- Reading the article affected my opinion of the writer.
- My attending a meeting of the school board affected my opinion of how well the principal was doing her job.
- His hitting a home run will affect my vote on the MVP of the game.
- The rate of pay affects how I feel about my job.
Here are some examples of effect used as a noun.
- The effect of our meeting is that I now fully agree with you.
- The effect of the recession has been financial ruin for many people.
- He miscalculated the effect of his memo.
- The effect of the war was terrible.
"Effect" as a verb
"Effect" used as a verb goes beyond just being the stimulus or influence behind an action; as a verb "effect" refers to actually achieving a final result--to bringing about, to accomplishing, to bringing into being, to executing, to resulting in whatever the final result was intended to be.
Some people find the distinction between "affect" and "effect" used as a verb confusing. The following examples should help clear that up. Regardless of what the grammar or spellcheck program on your computer tells you, the following examples are correct (this is a reminder that many times such computer programs are mistaken where correct grammar is concerned).
In these examples, "effect" is used to indicate that an actual result is achieved. Just remember that where the intended result is actually accomplished, "effect" is the correct verb to use. Where some action is merely stimulated or influenced by something, "affect" is used.
- Every administration hopes to effect a peace treaty in the Middle East.
- Rest assured that the new CEO will effect many changes in our company.
- The treatment effected a cure.
- The epidemic caused the politicians to effect new standards of sanitary practices.
Other uses of "affect" and "effect"
One can go to expanded dictionaries and grammar books and sometimes find examples of unusual, very occasional, or outdated uses of these two words. Doing so simply confuses one's understanding of the correct uses of these two words. The examples in this slide show cover the vast majority of uses of "affect" and "effect" that most of us will ever come across or have occasion to use.
For additional information consult The Chicago Manual of Style (16th Edition) and Merriam-Webster's Collegiate Dictionary (Eleventh Edition). Note: many companies use "Webster" and "collegiate" in the names of their dictionaries. Merriam-Webster's Collegiate is the dictionary definitely recommended for information about the definition and proper use of words.