Parts of Speech and Word Classes

In this section, we will place words into their part-of-speech categories and determine whether those categories are open or closed classes. Lexical categories (nouns, verbs, adjectives, and adverbs) are open classes, meaning that we can easily produce new words, or neologisms, belonging to these categories. Functional categories (prepositions, conjunctions, determiners, auxiliaries, etc.) are closed classes, which means we cannot or otherwise do not often invent new words belonging to these categories.

We will use the words in the following sentence as examples:

  I will walk quickly over the two small hills.

• I
  • Part of Speech: Pronoun (closed*)
• will
  • Part of Speech: Auxiliary (closed)
• walk
  • Part of Speech: Verb (open)
• quickly
  • Part of Speech: Adverb (open)
• over
  • Part of Speech: Preposition (closed)
• the
  • Part of Speech: Determiner (closed)
• two
  • Part of Speech: Number (closed**)
• small
  • Part of Speech: Adjective (open)
• hills
  • Part of Speech: Noun (open)

*Note: Pronouns are typically considered a closed class, but in recent years new pronouns have seen use especially by LGBTQ people in online spaces.

**Note: a number, or quantitative adjective, is a subclass of adjectives. Even though adjectives are an open class, we do not often see new numbers. The only way to come up with a new number is to follow established rules about how numbers are named. This puts numbers in an odd spot because, like pronouns, they belong to a semi-closed class within an open class.