Of course the simple fact that you say there is such rule is more than enough for me to believe it.
I just asked for a reference because since you always gifts us some really important ones, I thought you had it handy.
***** NOT A TEACHER *****
Hello, Ymnisky.
(1) You are much too kind.
(2) When it comes to language, everyone should be super humble.
I realize that I know very little about my native tongue. That's why
grammar is my hobby.
(3) If I understand your question correctly, you want to know the
authorities who support such sentences as these:
(a) My brother, Tom, is a doctor. = I have one brother. He is a doctor.
The two commas indicate that the information is extra. If I said, "My
brother is a doctor," that would be completely correct.
(b) My brother Tom is a doctor. = I have at least two brothers. I could
not erase Tom without destroying the integrity of my statement. That is
why there are no commas. It is Tom (not George) who is the doctor.
(c) Tom, my brother, is a doctor. Here it is impossible to know how many
brothers that I have. As you see, if you erase "my brother," the sentence
is still true: Tom is a doctor. But I want you to know that Tom and I
are related.
*****Below are my sources. There are millions (OK! dozens) of such
sources. Yes, many of them are old -- as am I. But I doubt these rules
have changed. High school teachers still try -- with varying degrees of
success -- to explain those 3 types of sentences above.
*****All of the words (including the words in parentheses are the
authors'). [My comments are in brackets]
***** Appositives are set off with commas:
Her husband, Tom, arrived. (She has only one husband.)
US NEWS & WORLD REPORT [magazine] Stylebook, 1994.
*****"They ate dinner with their daughter Julie. (Because they have
more than one daughter, the inclusion of Julie's name is critical if the
reader is to know which daughter is meant.)
"They ate dinner with their daughter Julie and her husband, David."
(Julie has only one husband. If the phrase read "and her husband David,"
it would suggest that she has more than one husband.)
THE ASSOCIATED PRESS STYLEBOOK, 1994.
*****A word in apposition is usually set off by commas
Jeanne DeLor dedicated the book to her only sister, Margaret.
[Just as you said, the word "only" would certainly make things
clearer.]
If the appositive has a restrictive function, it is not set off by commas.
My son Michael was the first one to reply.
Walpole had borrowed the bread slice from his friend Teetering.
THE CHICAGO MANUAL OF STYLE, 1993 [This book used by many
professionals.]
***** However, "Henry Little, my cousin," implies neither restriction
nor nonrestriction.
MODERN AMERICAN USAGE by Wilson Follett, 1980.
*****
As usual, it would be a pleasure to read any comments that you may
have. I believe that some of the in-house experts are professional
writers, so they can do a much better job than I in explaining this.
***** Thank you SO much *****
