affect to influence, to pretend (verbs); feeling (noun)
effect a result; being in operation (nouns); to make happen (verb)
Examples
Self-concept affects learning.1
She affected intellectualism by wearing glasses and using long words
Her affect is always sour in the morning.
One effect of lunar gravity is tides.
The new state income tax was in effect last fall.
The president effected a new policy on international trade.
Notes 1
Most often affect is used as a verb and effect is used as a noun. Something that affects you will have an effect on you.