gerund is a noun, of which it should be possible to say clearly whether, and why, it is in the subjective, objective, or possessive case, as we can of other nouns. That the distinction is often obscured, partly in consequence of the history of the language, will be clear from one or two facts and examples.
1. The man is building contains what we should all now call, whether it is so or not historically, a participle or verbal adjective: the house is building (older but still living and correct English for the house is being built) contains, as its remarkable difference of meaning prepares us to believe, a gerund or verbal noun, once governed by a now lost preposition.
2. In He stopped, laughing we have a participle; in He stopped laughing, a verbal noun governed directly by the verb; in He burst out laughing, a verbal noun governed by a vanished preposition.
3. Present usage does not bear out the definite modern ideas of the distinction between participle and gerund as respectively adjective and noun. So long as that usage continues, there are various degrees of ambiguity, illustrated by the three following examples. It would be impossible to say, whatever the context, whether the writer of the first intended a gerund or a participle. In the second, a previous sentence would probably have decided the question. In the third, though grammar (again as modified by present usage) leaves the question open, the meaning of the sentence is practically decisive by itself.
Can he conceive Matthew Arnold permitting such a book to be written and published about himself?—Times.
And no doubt that end will be secured by the Commission sitting in Paris.—Times.
Those who know least of them [the virtues] know very well how much they are concerned in other people having them.—Morley.
In the second of these, if sitting is a participle, the meaning is that the end will be secured by the Commission, which is described by way of identification as the one sitting in
