+228+. You recall that in our first lesson we studied concerning the
four different kinds of sentences which we use in expressing our
thoughts, the _assertive_, the _interrogative_, the _imperative_ and the
_exclamatory_. The interrogative sentence is the form which we use in
asking a question, _interrogative_ being derived from the Latin _inter_,
meaning _between_, and _rogare_, _to ask_, meaning literally _to ask
between_. The interrogative sentence differs from the assertive sentence
in the arrangement of the words; for in order to ask questions, we
usually place the predicate, or part of it at least, before the subject,
thus:
_Can_ you _use_ good English?
_Did_ you _spell_ the word correctly?
_Has_ he _studied_ grammar?
In these sentences, you note that the helping verbs, _can_, _did_ and
_has_, are placed first instead of the subject. It is by this
arrangement that we put the sentence in the interrogative form.
+229.+ Frequently, however, in asking questions we wish to ask
concerning a person or thing whose name we do not know. So we need a
word to refer to the unknown object. See how these uses of words grow
out of our need! We have three interrogative pronouns, _who_ and _which_
and _what_, that we use to meet this need. Notice the use of these three
pronouns in the following sentences:
_Who_ wrote the Communist Manifesto?
_Which_ of the two men is the better known?
_What_ are the closing words of this famous document?
In these sentences, _who_ and _which_ and _what_ are the interrogative
pronouns, used to ask questions concerning the unknown persons or
objects.
+230.+ +Who refers only to human beings or to personified objects.+
+Which refers either to human beings, animals or things.+
+What refers only to things.+
_Which_ and _what_ have the same form for both the subject and the
object. _Who_ has a different form for all three forms, the subject
form, the possessive form, and the object form. It uses the same form,
however, both in singular and plural.
_Subject form_ _Possessive form_ _Object form_