WARNING: Grammar lesson ahead.
If you ever knew what a “participle” was, you may have forgotten. Same with the word “gerund.” And if you ever heard the term “fused participle,” you probably zoned out completely.
The concept of a “fused participle,” though, is a good one to know, if sometimes disputed and difficult to understand. But let’s try.
“He can’t stand me knitting,” for example, means his animus is aimed at “me”; maybe he can’t stand that “me” is knitting instead of cooking. “He can’t stand my knitting,” though, means the “knitting” is the target, not “me.” And since the knitting belongs to “me,” it’s “my knitting,” a possessive.
“Knitting” here is a participial form of the verb “to knit.” But it’s not acting a verb in this sense; here it’s a noun. A verb that plays the part of a noun is called a “gerund.”
The Brothers Fowler started the trouble when they coined the term “fused participle” in their 1906 book The King’s English to signify when that gerund is not accompanied by a possessive, but by a plain noun or pronoun. The concept is confusing enough that it took up two and a half pages in the 1926 first edition of Modern English Usage, by H.W. Fowler, whose brother F.G. Fowler had died in 1918.
In the “knitting” sentence, the possessive is easy to see. But not so in many other sentences. For example: “The defense attorney objected to the prosecutor claiming prejudice on the part of the judge.”
The test of whether that is a “fused participle” is relatively easy: “Claiming” could be replaced with the noun “claim,” so “claiming” is a gerund/noun, so “prosecutor” should be possessive. Trying to replace the “-ing” word with a noun can help you see if the word preceding it should be a possessive.
Beware, though, that not every “-ing” word is a gerund. Some are merely the present participle of the verb, as in “We are happy with the woman who is knitting our baby’s booties.” (The participial verb is accompanied by an auxiliary verb, usually a form of “to be.”) And that “-ing” form also figures in danglers. Sometimes the difference is whether there’s a direct object involved: “Thanks for indulging me” is fine, but “thanks for indulging me being late” grates on the ear and should be “thanks for indulging my being late.”
The good news is that the fused participle, which Fowler called “grammatically indefensible,” has fewer and fewer defenders. Modern advice might be to see whether that “-ing” gerund can easily be mistaken for a verb, and if it can be, don’t worry about it. Garner’s Modern American Usage puts the “garden-variety fused participle” (I can understand him not wanting to participate) at Stage 3 on the five-stage Language-Change Index, meaning Fowler be damned.
The better news is that few fused participles will trip readers up so badly that the point is obscured. The ones that will probably involve personal pronouns like “me” rather than nouns like “prosecutor.” And if the repair sounds clunky or not idiomatic, let the fusion run its course.
So why put you through all that if it really doesn’t matter? Because it won’t matter, until it does, when your readers calling will let you know.