The following is taken from the Language Log: A Participle too far?
Originally Posted by Dawnstorm
The Cambridge Grammar of the English LanguageThere's an excellent paper on the topic called Ing forms and the progressive puzzle: a construction-based approach to English progressives by Seung-Ah Lee. Journal of Lingistics 43 (2007), 153-159. She writes:
has a section (p. 82) with the heading "A distinction between gerund and present participle can't be sustained
". Some highlights:
Historically the gerund and present participle of traditional grammar have different sources, but in Modern English the forms are identical. No verb shows any difference in form ..., not even be. [Thus] we reject an analysis that has gerund and present participle as different forms syncretised throughout the class of verbs. We have therefore just one inflectional form of the verb marked by the -ing suffix; we label it with the compound term 'gerund-participle' ..., as there is no reason to give priority to one or the other of the traditional terms. [...] This grammar also takes the view that even from the point of view of syntax (as opposed to inflection) the distinction between gerund and present participle is not viable, and we will therefore also not talk of gerund and present participle constructions [...].
"A closer look at this approach, however, reveals that it faces a serious problem. Notice that Huddleston (2002b: 1220) includes all constructions headed by 'gerund-participle' verbs under a single category 'gerundparticipial clauses' This lumping together of two different constructions obscures the all-important point that one, but not the other resembles noun phrases. Contrary to pedagogical grammarians, generative syntacticians disregard the formal identity between present participles and gerunds. Instead, they have tended to favour unifying derived and gerundive nominals."