Gerunds and present participles

Traditional English grammar distinguished between gerunds and present participles. Both terms refer to the non-finite verb form ending in -ing (standing, swimming, etc.); traditionally, the former was applied when the verb form was acting in some sense like a noun (say, as the subject or subject of a verb or preposition), and the latter when it was acting in some sense like an adjective. The analogous distinction is very clear in Latin, where gerunds and participles are declined as nouns or adjectives, but the line is blurrier in English, and many modern linguists reject this distinction. The Cambridge Grammar of the English Language, a widely respected descriptive grammar by Rodney Huddleston and Geoffrey Pullum, uses the term gerund-participle, and lists its various uses without commenting on which might be considered nominal and which adjectival.

Insofar as there is a distinction between gerunds and present participles, it is generally fairly clear which is which; a gerund-participle that is the subject or object of a prepositions is a gerund if it refers to the performance of an action (but note that present participles may be used substantively to refer to the performer of an action), while one that modifies a noun attributively or absolutely is a participle. The main source of potential ambiguity is when a gerund-participle follows a verb; in this case it may be seen either as a predicate adjective (in which case it's a participle), or as a direct object or predicate nominative (in either of which cases it's a gerund). In this case, a few transformations can help distinguish them. In the table that follows, ungrammatical sentences are marked with asterisks, per common linguistic practice; note that the transformations all produce grammatical sentences with similar meanings when applied to sentences with gerunds, but either ungrammatical sentences, or sentences with completely different meanings, when applied to sentences with participles.Transformation Gerund use Participle use
(none) John suggested asking Bill. John kept asking Bill.
passivization Asking Bill was suggested. *Asking Bill was kept.
pronominal substitution John suggested it. John kept it.
Use as a noun John suggested the asking of Bill. *John kept the asking of Bill.
Replacement with a finite clause John suggested that Bill be asked. *John kept that Bill be asked.
Use with an objective or possessive subject John suggested our asking Bill. *John kept his asking Bill.
Clefting Asking Bill is what John suggested. *Asking Bill is what John kept.
Left dislocation ?Asking Bill John suggested. *Asking Bill John kept.


None of these transformations is a perfect test, however.