The Difference between Affect and Effect.
What you are most likely looking for:
Affect (Verb): To Have an influence on or to change in some way.
Example:
His lack of a high school degree affects my decision to vote for him.
vs
Effect (Noun): A change or result that is the outcome of an action or cause.
Example:
The effect of crashing my car is that I now have to pay more for insurance.
Other uses:
Effect (Noun): Something that creates a specific impression or supports a general design or intention.
Example:
The sound effects produced a frightening ambience.
Effect (Verb): To produce a result, or to cause something to happen.
Example:
The purpose of the stimulus plan was to effect an economic recovery.
Effects (Noun): Someones personal belongings.
Example:
The officer searched through all of my personal effects
Affect (Noun): Used in Psychiatry to describe the observable behaviors or actions that express an emotional state.
Example:
His affects cause me to believe that he is angry.
(This last usage of "Affect" is very rare, and is almost never used outside of psychiatry, psychology or journalism.)