That is often used as a relative, to prevent the too frequent repetition of who and which. It is applied both to persons and things; as, "He that acts wisely, deserves praise; Modesty is a quality that highly adorns a woman."
NOTES.
1. Who should never be applied to animals. The following application of it is erroneous:—"He is like a least of prey, who destroys without pity." It should be, that destroys, &c.
2. Who should not be applied to children. It is incorrect to say, "The child whom we have just seen," &c. It should be, "The child that we have just seen."
3. Which may be applied to persons when we wish to distinguish one person of two, or a particular person among a number of others; as, "Which of the two? Which of them is he?"
4. That, in preference to who or which, is applied to persons when they are qualified by an adjective in the superlative degree, or by the pronominal adjective same; as, "Charles XII., king of Sweden, was one of the greatest madmen that the world ever saw;—He is the same man that we saw before."
5. That is employed after the interrogative who, in cases like the following; "Who that has any sense of religion, would have argued thus?"
When the word ever or soever is annexed to a relative pronoun, the combination is called a compound pronoun; as, whoever or whosoever, whichever or whichsoever, whatever or whatsoever.