Accept and Except
Accept is a verb that means to take something offered.
I accept your gift.
Except is a preposition that means not including a person or thing.
I will eat all of the apples, except for the red one.
Advice and Advise
Advice is a noun that means a recommendation about something.
My advice to you is to stop sucking your thumb.
Advise is a verb that means to offer advice.
I advise you not to play with that bee.
Affect and Effect
Affect is usually a verb that means influencing something or somebody.
The waves affect my stomach.
Effect is usually a noun that means result.
One effect of studying is good grades.
Alternate and Alternative
Alternate is an adjective that means every second one or in turns.
We will alternate work shifts.
Alternative is an adjective that means that something is available as an option.
An alternative to pork is chicken.
Among and Between
Among is a preposition that means more than two things or persons.
Among the games in the store, this one is best.
Between is a preposition that involves only two things.
Between purple and black, I like purple better.