CONSTRUCTION OF POSSESSIVE FORMS.
As the possessive is the only case of nouns that has a distinctive inflection, it is only with this case that mistakes can occur in construction.
+Caution+.—When several possessive nouns modify the same word and imply common possession, the possessive sign is added to the last only. If they modify different words, expressed or understood, the sign is added to each.
+Explanation+.—William and Henry's boat; William's and Henry's boat. In the first example, William and Henry are represented as jointly owning a boat; in the second, each is represented as owning a separate boat—boat is understood after William's.
+Remark+.—When the different possessors are thought of as separate or opposed, the sign may be repeated although joint possession is implied; as, He was his father's, mother's, and sister's favorite; He was the King's, as well as the people's, favorite.
+Direction+.—Correct these errors, and give your reasons:—
1. The Bank of England was established in William's and Mary's reign. 2. Messrs. Leggett's, Stacy's, Green's, & Co.'s business prospers. 3. This was James's, Charles's, and Robert's estate. 4. America was discovered during Ferdinand's and Isabella's reign. 5. We were comparing Caesar and Napoleon's victories. 6. This was the sage and the poet's theme.
+Explanation+.—If an article precedes the possessive, the sign is repeated.
7. It was the king, not the people's, choice. 8. They are Thomas, as well as James's, books.
+Caution+.—When a possessive noun is followed by an explanatory word, the possessive sign is added to the explanatory word only. But, if the explanatory word has several modifiers, or if there are more explanatory words than one, only the principal word takes the sign.