Is that one word or two?
A very common trap, that many native speakers also fall into, is this one:
Jill wears her everyday jeans to the office every day and her designer jeans on the weekends.
As one word, it's an adjective and means regular, normal, nothing special. As two words, it's a time expression, just like 'every month' and 'every year'.
As one word, 'everyone' means 'all people' but the verb that follows is 3rd person singular (while 'people' is followed by 3rd person plural):
Everyone knows Jack's start-ups. Every one of them has been a huge success.
As two words, the focus is on each one individually.
Here are some more examples:
Jill's team members arrived all together for the meeting; altogether there were seven of them.
After the meeting Jill rested awhile by putting her feet up and napping for a while.
Jack won't be taking over any more companies; he can hardly manage the current four companies anymore.
Anyone can ask Jack for advice; he'll help any one of his staff.
Jill is happy to work anyplace but can't work in any place that doesn't have an espresso machine.
Jack can't think of any way to stop Jill from drinking so much coffee. Anyway, who cares if it helps her to work long hours.
Jill's working on her keynote for next week anytime she has any time.
Jack and Jill are all ready to go to the conference; in fact, they've already left!
If you're not sure about the differences, please email me with any questions.
© 2015 Christina Wielgolawski