Every is a determiner.
Every meaning ‘each member of a group’
We use every + singular noun to refer individually to all the members of a complete group of something:
There’s a photograph on the wall of every child in the school.
Try to answer every question.
When every refers to the subject of the clause, we use a singular verb:
Every player wants to be in a winning team.
Every player want…
Every cook needs good knives and a chopping board.
The negative of every is normally not every:
Not every noun has a plural form.
We use singular pronouns and possessives to refer back to every + noun, especially in more formal styles, and especially when what we refer to is not human:
Every store has a manager in charge of it.
Every area has its own park.
In less formal styles, the pronoun or possessive may be plural:
Every student gets a laptop. They have to give it back at the end of the course.
Every user has their own password.
Every: regular situations
We use every with a singular noun to refer to something that happens regularly:
The festival is held every August in Budapest.
I leave the house every morning at 6 am.
I leave the house every mornings at 6 am.
We use every with a number and a plural noun to refer to regular intervals of time or numbers:
There are buses into town every ten minutes.
He now works from home, travelling to Amsterdam every two weeks.
Every day or everyday?
We write two words when every day means each day. The adjective everyday is one word. It means ‘normal’ or ‘usual’:
The boys meet up every day in the park.
The boys meet up everyday in the park.
In the Soviet Union, poetry was at the centre of everyday life.
We often use single with every to emphasise each member of a complete group of people or things:
He was the only player who played in every single match last season.
I’ve got to photocopy every single page.
Every one or everyone?
We use every one, written as two words, to refer back to a noun we have already mentioned:
I received more than a hundred letters from him while I was away and I’ve kept every one.
Everyone, written as one word, means ‘every person’:
Everyone enjoyed themselves.
We use every one of before pronouns and determiners:
There are 107 two-letter words in the dictionary and John Catto, an Aberdeen lorry driver, knows every one of them.
When Jenkins joined the bank, one of his first acts was to make every one of the bank’s employees reapply for their jobs.
We use every other to mean ‘alternate’:
We worked every other Sunday. (One Sunday he worked, the next Sunday he didn’t work, the next Sunday he worked, etc.)
He works in Germany every other week. (One week he works in Germany, the next week he doesn’t, the next week he does, etc.)
Every: typical errors
We don’t use every on its own, without a noun or without one:
There were five rooms. Every room was decorated in a different style.
Every was decorated in a different style.
We don’t use every with a plural noun:
I go swimming every day.
I go swimming every days.