Each, every

How to use each and every correctly.

Each, every
Each is used if we mean an individual member of a group.
Every can also be used.
We have send the invitation to each / every business partner.
Each of is used if we mean all members of a group and we include a possessive adjective such as our, my, their, etc.
Every cannot be used in this case.
We have sent the invitation to each of our friends.
every of our friends
Every is used with a plural noun when it is followed by a number. Each cannot be used in this case. I visit my mother every two months / every other day / every second week.