◊ 'everyday'
Everyday is an adjective. You use it to describe something which is normal and not exciting or unusual in any way.
People could resume a normal everyday life.
...things that were common and everyday to him but luxuries to them.
◊ 'every day'
Every day is an adverbial. If something happens every day, it happens regularly each day.
Shanti asked the same question every day.
Useful english dictionary. 2012.