learn the rule
affect / effect
affect is a verb. It means to influence or have an impact on something.
- The cold weather will affect the potato harvest.
- Don't let his opinion affect your decision.
effect is a noun. It means the result or outcome of something.
- The effect of the rain on your sock was unfortunate.
- This rule has a positive effect on your writing.
- The effect of your spelling on people's opinion of you is profound.
- The effect is that you look stupid.
Yes, there are exceptions
effect can occasionally be a verb, meaning to bring something about, as in "effect change". This is rare in everyday writing.
affect can be a noun in psychology, referring to mood or emotion. Even rarer.
If you're not writing a corporate strategy doc or a clinical paper, you can safely treat affect as the verb and effect as the noun.
A handy test: if you can put "the" or "an" in front, you want effect (the effect, an effect). If something is being done, you want affect.
Getting it wrong has an effect. It affects how stupid you look.