Currently, I've been revising my mystery novel and because I'm forgetful, had to keep looking up certain words.
For example, I've had a time remembering when to use the word EFFECT and AFFECT. It's difficult to remember because they are so close in meaning.
EFFECT means something that is produced (noun) by an agency or cause; result; consequence: Exposure to the sun had the effect of toughening his skin.
EFFECT means meaning or sense; purpose or intention: She disapproved of the proposal and wrote to that effect.
AFFECT means to impress the mind or move the feelings of: The music affected him deeply.
The majority of the time you use affect with an a as a verb and effect with an e as a noun.
The arrows Affected Aardvark. The Effect was Eye-popping.
Source: Grammar Girl