Note 19 — Chapter III · PRONOUNS
Reading edition
The pupil should not “supply nouns” in such sentences as these. For example, it is unscientific to expand the first sentence into “This [morning] is a fine morning,” and then to parse this as an adjective. It is even more objectionable to expand the fifth sentence by inserting thing or the like after this. The plan of “supplying” unexpressed words (as being “understood”) tends to confuse real distinctions of language, and should never be resorted to when it can be avoided.↑