everyone
pron. A1 Beginner Oxford US //ˈɛvɹiˌwən// UK //ˈɛvɹɪwˌɒn// ev·ery·one
pron. every person in a group. You use it when you are talking about all the people in a place or situation.
pron. every person; all people in a particular group or the world at large.
Everyone in the class passed the test.
The party was a huge success and everyone had a wonderful time dancing.
While the policy was designed to benefit the majority, it soon became clear that everyone involved would need to make significant sacrifices to ensure its long-term success.
From Middle English everichon. By surface analysis, every + one.
Usage
Always takes a singular verb despite referring to multiple people.
Pitfall
Everyone are happyEveryone is happyEven though it refers to many people, the pronoun is grammatically singular and requires a singular verb.