Comment by mplanchard

For their more common meanings, like in your paragraph, as a verb you want affect, and as a noun, effect. So, when in doubt, use that as a rule of thumb.

However, both have alternative meanings as the other part of speech.

Affect as a noun means emotion or disposition, and is mostly used in psychology. Your psychologist may say you have a depressed affect.

Effect as a verb means to bring about. You might say that a successful protest effected change in society.

As a verb, in addition to “have an impact on,” affect can also mean “to pretend to have,” like “she affected an air of mystery,” although this is less common.