Quote Originally Posted by Throbert McGee View Post
If you say "Who did it?" -- "It was he!", it sounds rather pompous, and you may remind people of Bela Lugosi in the 1931 version of Dracula. (He's always parodied as speaking with hyper-correct grammar: "It is I, Count Dracula!"; though 99.99% of English speakers would say, for example, "It's me, Buffy Summers.")
Just to clarify things: Bela Lugosi's use of the the pronoun in the nominative case was grammatically correct, but it is true that one may say, it wasn't colloquially correct. The situation is exactly the same as with "he" and "she" - in both cases we have a copula followed by a pronoun, in which case it is supposed to agree with the subject, which is nominative.

Quote Originally Posted by CoffeeCup View Post
If I wrote a book, what should I say in a passive voice: "The book was written by me/myself" ?
The reflexive pronoun is used only in conjunction with the subject. Therefore you should use "me" in the given example, as "the book" has nothing to do with "myself." If the sentence had been "I wrote the book me/myself" you should use "myself," as it is used in conjunction with the subject.