The rules about subject-verb agreement
Don't be misled by words between the subject and the verb
The best thing about birthdays (is or are?) the presents.
Leave out 'about birthdays'.
The best thing is the presents.
So the sentence should read: The best thing about birthdays is the presents.
Subjects joined by "and" require a plural verb
The White Rabbit and the Red Queen are two characters from Alice's Adventures in Wonderland.
The verb agrees with the nearest subject when two or more subjects are joined by ...
The cousins or Aunt Matilda herself is going to arrange the party.
Aunt Matilda or the cousins are going to arrange the party.
either ... or
Either Aunt Matilda or the cousins have drunk all the brandy.
Either the cousins or Aunt Matilda has drunk all the brandy.
neither ... nor
Neither Aunt Matilda nor the cousins have drunk all the brandy.
Neither the cousins nor Aunt Matilda has drunk all the brandy.
not only... but also
Not only Aunt Matilda but also the cousins have drunk all the brandy.
Not only the cousins but also Aunt Matilda has drunk all the brandy.
I'll be back with another one ;)
Thanks Bro ..!
My pleasure bro !
really I didn't know . but now I know . thanks a lot brother for your diligence. i really have teached from that group very much :)