verb and noun
Not effect (which is usually a noun, but sometimes a verb). For a discussion of affect vs. effect, read Chapter 8 in the section on Common Grammatical Mistakes. Click here for the beginning of that discussion.
Example: This new law will affect the economy. verb
Example: This new law will have an effect on the economy. noun
Example: The law will effect many changes in the way we do business. verb
Example: His nervous affect betrayed his guilt. noun