Which is grammatically correct and why?
Everyone put on his coats and went home.
Everyone put on their coats and went home.
As the other answers might suggest, we could start by considering four alternatives here, to identify two problems of agreement:
I agree with Jay in ruling out forms 2 and 3, which distract us with the question of whether each person had one coat (as I assume you meant), or whether the people have several coats each (form 2) or share one coat (form 3), considerations that seem silly.
So we are down to choosing between forms 1 and 4.
Many native speakers would certainly say form 4 in ordinary speech. They seem to think of "everyone" as meaning "they all," and proceed as if they had actually said that instead: they all put on their coats.
To me, that seems wrong. Everyone means "each person," and is singular, allowing only form 1. But there are some sticky points about choice 1.
First, I guess, form 1 sounds stilted. But secondly, there might be contexts in which the listener cannot be trusted to follow you in treating "everyone" as singular. For example, consider this story:
John invited his co-workers to meet him after work. At the end of the day everyone went back to his house.
That story seems to dare the reader to guess whether each person went to his own house, or whether all people met at John's house.
So for those people who are conscious of the problem, perhaps the best solution would be to think about each use of such a construction. Treat "everyone" as singular, but if this results in confusing prose, in which the reader cannot tell whom you refer to, rewrite using legitimately plural words instead:
John invited his co-workers to meet him after work. At the end of the day...
a) they all went back to his house; or
b) each person went to his own house.
"Everyone" is a funny word. It is treated as singular for purposes of noun/verb agreement. For example, we say, "Everyone is happy", NOT "Everyone are happy". But when you refer back to "everyone" from later in the sentence, you can use either a singular or a plural. You can say, "Everyone put on their coats" or "Everyone put on his coat".
You should not say, "Everyone put on his coats", because that implies that each person had more than one coat. (Well, unless each person did have more than one coat.)
As far As i know.. Everyone, everybody, everything, and everywhere are indefinite pronouns and We use them to refer to a total number of people, things and places. We write them as one word:
For instance :
His name was Henry but everyone called him Harry. All your clothes are clean. I washed everything yesterday.
The answer to your questions is that When we want to refer back to everyone or everybody and we don’t know if everyone is male or female, we use him or her and his or her. In informal styles, we use plural pronouns they, their and them:
Everybody has a team leader in charge of him or her.
Not everyone has his or her own desk.
Has everyone got their coats? (more informal)
Has everybody handed their homework in on time?
i hope it helps.