In examples 11 and 12, “no” and “yes” are not used as sentence words requiring the punctuation of Sentence 56; but they are mere expletives, introducing something more emphatic than what precedes. Each takes the punctuation of an expletive, namely, a comma or commas.
13. The man gave many proofs of complete indifference to death, while he was doing his duty.
14. On the battle-field the man gave many proofs of complete indifference to death, while at home he seemed almost a coward.
No. 13 is an Atlantic Monthly sentence. As “while” is here equivalent to during the time, the use of the comma, which gives “while” the adversative meaning exhibited by “while” in No. 14, is wrong. In No. 14 “while” is almost equivalent to “but,” and here loses the sense of time.
15. The Lord has blessed thee, since my coming.
No. 15 is a clause from Gen. xxx, 30, punctuated as it appears in Webster’s New International. As “since” is a preposition, equivalent in meaning to during the time subsequent to, the use of the comma before it is clearly a typographical error.
CHAPTER VII
COMMA, SEMICOLON, COLON, AND PERIOD—THEIR DIFFERENTIATION
As has already been seen, we determine what mark of punctuation is helpful at any point in written or printed language by the sense relation between two groups of words and by the degree of separation between such groups. The degrees of separation cannot be so accurately classified that there will not be much apparent and some real inconsistency in the punctuation of the most careful writer, and much more in the uses of marks by different writers.