After “of”
By a peculiarity of idiom the possessive sign is used with a noun in the objective; as, “This is a story of Lincoln’s,” “That is a letter of the President’s,” “A patient of Dr. Butler’s,” “A pupil of Professor Ludlam’s.”
In ordinary prose the custom of the best writers is to limit the use of the possessive chiefly to persons and personified objects; to time expressions, as, an hour’s delay, a moment’s thought; and to such idioms as for brevity’s sake.
Avoid such expressions as, “America’s champion baseball player,” “Chicago’s best five-cent cigar,” “Lake Michigan’s swiftest steamer.”
Somebody else’s
The question whether we should say “This is somebody’s else pencil,” or “This is somebody else’s pencil,” has been warmly argued by the grammarians, the newspapers, and the schools. If some leading journal or magazine were to write somebody else as one word, others would, doubtless, follow, and the question of the possessive would settle itself. The word notwithstanding is composed of three separate words, which are no more closely united in thought than are the three words some, body, and else. Two of the latter are already united, and the close mental union of the third with the first and second would justify the innovation.
But the words are at present disunited. A majority of the best writers still conform to the old custom of placing the possessive with else.
“People were so ridiculous with their illusions, carrying their fool’s caps unawares, thinking their own lies opaque, while everybody else’s were transparent.”—George Eliot.
Some make a distinction by placing the possessive with else when the noun follows, and with somebody when the noun precedes; as, “This is somebody else’s pencil,” and “This pencil is somebody’s else.” This distinction is not generally followed.