Here are 2 words that have almost the same meanings, but you cannot always use either one. Below are some rules for their uses.
Each – both (2 or more objects or people)
Every – all (3 or more objects or people)
Here is an example of when they have almost the same meaning:
I go to the festival every year.
I go to the festival each year.
The difference of the 2 sentences is that in the first sentence with every, we are thinking of the festivals in total. In the 2nd sentence with each, we are thinking of them more individually.
Here are some examples of when you can use only one or the other:
My kids each received a present. (Each is used before a verb.)
My kids every received a present. Incorrect
Santa gave a present to each of them. (Each is used before of.)
Santa gave a present to every of them. Incorrect (However, you can put ‘one’ after every and then it is okay. Santa gave a present to every one of them.)
He was using each hand equally. (Each used to describe 2 things.)
He was using every hand equally. Incorrect
Once every 2 weeks, I go to the doctor. (Referring to a regular event).
Once each 2 weeks, I go to the doctor. Incorrect