Relative Pronouns are such as relate, in general, to some word or phrase
going before, which is called the antecedent. They are _who, which_, and
_that_.
The word _antecedent_, comes from the two Latin words, _ante, before_,
and _cedo, to go_. Hence you perceive, that antecedent means going
before; thus, "The _man_ is happy _who_ lives virtuously; This is the
_lady who_ relieved my wants; _Thou who_ lovest wisdom, &c. _We who_
speak from experience," &c. The relative who, in these sentences,
relates to the several words, _man, lady, thou_, and _we_, which words,
you observe, come before the relative: they are, therefore, properly
called antecedents.
The relative is not varied on account of gender, person, or number, like
a personal pronoun. When we use a personal pronoun, in speaking of a
man, we say _he_, and of a woman, _she_; in speaking of one person or
thing, we use a singular pronoun, of more than one, a plural, and so on;
but there is no such variation of the relative. _Who_, in the first of
the preceding examples, relates to an antecedent of the mas. gend. third
pers. sing.; in the second, the antecedent is of the fem. gend.; in the
third, it is of the second pers.; and in the fourth, it is of the first
pers. plur. num.; and, yet, the relative is in the same form in each
example. Hence you perceive, that the relative has no peculiar _form_ to
denote its gend. pers. and num., but it always agrees with its
antecedent _in sense_. Thus, when I say, The _man who_ writes, _who_ is
mas. gend. and sing.; but when I say, The _ladies who_ write, _who_ is
feminine, and plural. In order to ascertain the gend. pers. and num. of
the relative, you must always look at its antecedent.
WHO, WHICH, and THAT.
_Who_ is applied to _persons, which_ to _things_ and _brutes_; as, "He
is a _friend who_ is faithful in adversity; The _bird which_ sung so
sweetly, is flown; This is the _tree which_ produces no fruit."
_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."