A few weeks ago, I mentioned here a CNN article “about the president making an unannounced stop.” Two readers emailed with the same question. Here’s Bill in Niskayuna, N.Y.: “I was taught that a noun ...

Though gerunds and present participles share the same -ing form, their grammatical roles differ: gerunds act as nouns, while participles act as verbs or adjectives. For example, 'Reading helps me ...