If the first four words are a part of the inscription, the fact must be shown; and it is shown in No. 28-3 by the quotation-marks. The use of small capitals in No. 28 is much more suggestive of an inscription than the use of the quotation-marks in No. 28-3.
In our next illustrative sentence, the grammatical connection within the sentence is perfect, but the sense changes. Here the dash is used to suspend the thought in preparation for the surprise to come. It is a rhetorical mark, for it indicates how the words would be spoken:
29. He never lacked a good word—from those who spoke his praise.
A speaker or a writer often wishes to repeat a part of or all that he has said, and then continue with his line of thought, using different words for emphasis, for exactness, or for other reasons. Or he may wish in this way to summarize what he has already said, completing the sentence with the summarizing word as the subject. There seems to be no grammatical relation between the summarizing group of words and what precedes them. The dash serves to show the break in the sentence, and is thus merely a rhetorical mark:
30. He has been unkindly—he has been shamefully treated.
31. Persecution, injustice, ruined fortune—all seemed insignificant.
The office of the dash in each of the above sentences might be performed by a blank space of equal length; but such space might not always be easily distinguished from the usual spaces between words.
Some English writers use dots or two or more periods where we use dashes in sentences like the above.
Our next illustrative sentence, with its modifications, shows a very useful and quite indispensable office of the dash. The sentence exemplifies one of the commonest errors made by good writers.
32. The expenditure of this vast sum is entrusted to school officers, trustees, inspectors, and commissioners.
32-1. The expenditure of this vast sum is entrusted to school officers: trustees, inspectors, and commissioners.
32-2. The expenditure of this vast sum is entrusted to school officers (trustees, inspectors, and commissioners).