Once you’ve learned all the basic rules of English grammar, you’ll find there are almost as many exceptions. Grammarly Director of Communications Allison VanNest explains some words that act in ways you might not expect.
1. Nouns with -ing endings. In the sentence “I am running,” “running” is part of the verb. But “I like running,” is a gerund, a form of verb that’s actually a noun. It can look confusing when possessive subjects are involved: Sally’s running took up a lot of time. To see if you’re using the word correctly, replace the gerund with a similar noun—such as “exercise,” in this case—to see if it still makes sense.
2. Nouns acting as adjectives. Sometimes nouns serve as adjectives. For example, “I ate off a paper plate.” “Paper” serves as an adjective in this sentence describing the type of plate. Sometimes, adjectival forms that make more sense, such as “I ate off a wooden plate,” instead of “I ate off a wood plate.”
3. Adjectives acting as nouns. Often, the English language makes collective nouns out of adjectives. “Hungry” usually serves as an adjective, as in, “The hungry dog begged for food.” Putting “the” in front of it can change it into a noun, “We must do more to help the hungry.”
4. Nouns acting as verbs. Just because a word is a noun doesn’t mean it might not someday serve as a verb. Technological terms often change from nouns into verbs, such as “texting.”
5. Adjective or adverb? While we all know that most “-ly” words are adverbs, there are some that are adjectives, such as friendly. In addition, some adverbs don’t end in -ly and may be either adjectives or adverbs, such as “slow” and “late.”
— Adapted from “Words Behaving Badly,” Allison VanNest, Grammarly.