The incorrect use of everyday as one word has become one of my pet peeves. I see it in print all the time. Because a spellchecker doesn’t know how the word is used, it accepts everyday as one word all the time. This simple rule will help you determine when to use everyday as one word and when to use two words: every day.
Use one word when everyday is used an adjective, that is, when it comes right before a noun and answers the question, “What kind?”
These are my everyday shoes.
Running into people I know is an everyday happening for me.
Let’s use the everyday tablecloth.
Use two words when every day is used as an adverb, that is, when it answers the question, “how often?” It often comes after the verb, but it can come at the beginning of a sentence too.
I walk to work every day.
Take this vitamin every day.
Every day we have this same conversation.