Grammar: Word classes

Overview

What is a word?

Words go together to make up groups and phrases, which in turn go together to make up clauses: 

The old junk was drifting aimlessly.

For most purposes, we could say that the word is the smallest unit of English grammar. In many cases, individual words cannot be broken down into smaller parts (the, old, junk, was, drift, aim). However, some words in English can be broken down into smaller parts (drift + ing, aim + less + ly). These separate parts are called morphemes:

There are two types of words in English

	lexical (or content) words
	grammatical words

By lexical words we mean words that have their own meaning or content:

By grammatical words we mean words that play a grammatical function. These words have a meaning but it is a grammatical meaning rather than a content meaning:

Grammatical, or function words form closed sets. This means that we can easily list the set of all function words in English. For example, we could list the complete set of personal pronouns (I/me, you (s), he/him, she/her, it, we/us, you (pl), they/them).

Content words form open sets or classes. Nouns and verbs are examples of open sets. We could not easily list all the nouns and verbs in English. One reason is that there are so many, but another reason is that the list is always expanding. New content words are continually being added to the language. This is the major difference between content words and function words. Only very rarely does a new function word get added to the language. Such an example at the moment may be the plural form of you as yous, which is heard in some varieties of English (especially in Australia).