But in 1 (b), 2 (b), and 3 (b), there are two points of difference from the others considered:  first, no antecedent is expressed, which would indicate that they are not relatives; second, a question is disguised in each sentence, although each sentence as a whole is declarative in form.  Thus, 1 (b), if expanded, would be, “Who stood behind?  We knew,” etc., showing that who is plainly interrogative.  So in 2 (b), what is interrogative, the full expression being, “But what had become of them?  They knew not.”  Likewise with which in 3 (b).

[Sidenote:  How to decide.]

In studying such sentences, (1) see whether there is an antecedent of who or which, and whether what = that + which (if so, it is a simple relative; if not, it is either an indefinite relative or an interrogative pronoun); (2) see if the pronoun introduces an indirect question (if it does, it is an interrogative; if not, it is an indefinite relative).

[Sidenote:  Another caution.]

128.  On the other hand, care must be taken to see whether the pronoun is the word that really asks the question in an interrogative sentence.  Examine the following:—­

1.  Sweet rose! whence is this hue
     Which doth all hues excel? 
     —­DRUMMOND

2.  And then what wonders shall you do
     Whose dawning beauty warms us so? 
     —­WALKER

3.  Is this a romance?  Or is it a faithful picture of what has
     lately been in a neighboring land?—­MACAULAY

These are interrogative sentences, but in none of them does the pronoun ask the question.  In the first, whence is the interrogative word, which has the antecedent hue.  In the second, whose has the antecedent you, and asks no question.  In the third, the question is asked by the verb.

OMISSION OF THE RELATIVES.

[Sidenote:  Relative omitted when object.]

129.  The relative is frequently omitted in spoken and in literary English when it would be the object of a preposition or a verb.  Hardly a writer can be found who does not leave out relatives in this way when they can be readily supplied in the mind of the reader.  Thus,—­

     These are the sounds we feed upon.—­FLETCHER.

     I visited many other apartments, but shall not trouble my reader
     with all the curiosities I observed.—­SWIFT.

Exercise.

Put in the relatives who, which, or that where they are omitted from the following sentences, and see whether the sentences are any smoother or clearer:—­

     1.  The insect I am now describing lived three years,—­GOLDSMITH.

     2.  They will go to Sunday schools through storms their brothers
     are afraid of.—­HOLMES.