(2) It has three case forms,—who, whose, whom.
(3) The forms do not change for person or number of the antecedent. In sentence 4, who is first person; in 5, whose is second person; the others are all third person. In 1, 2, and 3, the relatives are singular; in 4, 5, and 6, they are plural.
Who referring to animals.
112. Though in most cases who refers to persons there are instances found where it refers to animals. It has been seen (Sec. 24) that animals are referred to by personal pronouns when their characteristics or habits are such as to render them important or interesting to man. Probably on the same principle the personal relative who is used not infrequently in literature, referring to animals.
Witness the following examples:—
And you, warm little housekeeper [the cricket], who class With those who think the candles come too soon.—Leigh Hunt.
The robins...have succeeded in driving off the bluejays who used to build in our pines.—Lowell.
The little gorilla, whose wound I had dressed, flung its arms around my neck.—Thackeray.
A lake frequented by every fowl whom Nature has taught to dip the wing in water.—Dr. Johnson.
While we had such plenty of domestic insects who infinitely excelled the former, because they understood how to weave as well as to spin.—Swift.