Everyday vs. every day

Everyday is an adjective used to describe things that occur every day. In the two-word phrase every day, the adjective every modifies the noun day, and the phrase usually functions adverbially. So, for example, every day you eat breakfast. You brush your teeth every day. Maybe you go for a walk or have a drink every day. These are everyday activities. 

Examples

For example, these writers use everyday and every day correctly:

When Hirohito spoke, few could understand him because he used a language so formal that it was unintelligible to everyday people. [Washington Post]

His owner says he’s excited to go to work every day. [Calgary Herald]

Is the trend for using high-end ingredients in everyday recipes going to take off outside restaurants and TV studios? [Guardian]

In both our cases, every day spent off school was a day spent playing video games. [Sydney Morning Herald]

While everyday is usually used to mean commonplace or ordinary, it can also mean daily—for example:

Johnson likely would enter the season as the club’s everyday second baseman. [AZ Central]

Outside of J.D. Drew, the Red Sox have what looks like a pretty good everyday lineup on the field tonight. [Boston Globe]