"My class is having a party"
"Everyone is bringing food or drinks"
Which grammar rule says that we use the verb "to be" in singular?
***** A NON-TEACHER'S COMMENT *****
(1) Nightmare has given us an excellent answer.
(2) I only wish to add a few points:
(a) It might be easier for you to remember that "everyone"
takes a singular verb if you study the word. Actually it is
"every
one." But it is spelled as one word nowadays. Just
like "every
body" is now "everybody." Therefore, the verb should
agree with "one" or "body."
(b) You are correct: it
isconfusing. We use a singular verb
(because of "one"), but the IDEA is plural. For example, here
is a sentence that I read in a book:
Everybody knows this,
don't they? The book says that it
would be ridiculous to write:
Everybody knows this, doesn't he or she?
(Credit for this example goes to Mr. Paul Dean, writing in the
[London]
Times Literary Supplement, cited in Mr. Bryan A. Garner's
A Dictionary of
Modern American Usage, page 268 of the 1998 edition.)
*****
(3) The matter of "class" can also be confusing. As Nightmare told
us, the word is usually singular: The class like
s the teacher very much./
That teacher's class
is always very well-behaved.
(a) "Class" is what the books call a "collective noun." That is,
sometimes it can be plural. Here is an example:
The class
are starting their research papers. (That is, the student
s
are starting their research papers. If there are 30 students, then
there will be 30 different research papers.) [I do not remember where
I read this. Sorry that I cannot give proper credit.]
Respectfully yours,
James