NOT A TEACHER
You may find this information useful, taken from the Longman Dictionary of Contemporary English.
It is often correct to use either each or every , but they have slightly different meanings.
Use each when you are thinking about the people or things in a group separately, one by one :
Each student came forward to receive a medal.
Each time you exercise, you get a little stronger.
Use every when you are thinking about the whole group of people or things together, with no exceptions :
Every student was given a prize.
You have to enter your password every time you log on.
► Do not use each after words such as 'almost', 'nearly', or 'not'. Use every :
Almost every window was broken.
Not every child enjoyed the party.