To affect means “to do something that produces an effect in something”. To effect means “to make something happen”. As a noun, effect means “the way in which something is changed; a result, or an outcome”. affect This decision will affect our lives. The disease affected his nervous system. Inflation affects the buying power of people. effect The new director effected (=caused) a positive change. The effect of having a new director was positive. Inflation has an effect on the buying power of people.