【明報專訊】In linguistics, the word "gerund" refers to a verb used as a noun in its "ing" form. Gerunds are associated with certain customary ways of saying things. Many learners of English are often confused as to when to use "gerunds" and when to use "infinitives". In most cases gerunds and infinitives are interchangeable. However, in certain circumstances, only "gerunds" are used and not "infinitives". The best way to learn how to use gerunds properly is through frequent practice. Grammatical rules might help; but, as the saying goes, practice makes perfect!