affect V.S effect

How do tax cuts affect the economy?
affect (v.) 指影響一件事情的動作。如：The divorce affects our kids；effect (n.) 指影響的結果。如：The effects of radiation on humans。輻射對人的影響。


Grammar Girl
So, most of the time, affect with an a is a verb and effect with an e is a noun


Rare Uses of Affect and Effect

So what about those rare meanings that don't follow the rules I just gave you? Well, affect can be used as a noun when you're talking about psychology--it means the mood that someone appears to have. For example, "She displayed a happy affect." Psychologists find it useful because they know that you can never really understand what someone else is feeling. You can only know how they appear to be feeling.

And, effect can be used as a verb that essentially means "to bring about," or "to accomplish." For example, you could say, "Aardvark hoped to effect change within the burrow."