In Linguistics, we observe how parts of language behave. When we find a set of words that all behave similarly, we can group them into a category, specifically, into a syntactic category. You might have learned about some of these categories as “parts of speech”. This unit gives an overview of the behaviour of the biggest categories.

You’ve probably learned that nouns are words that describe a person, place or thing. But when we’re studying morphology and syntax, we categorize words according to their behaviour, not according to their meaning.There are two elements to a word’s behaviour:

• What inflectional morphemes does the word take?
• What is the word’s syntactic distribution? In other words, what position does it occupy in a sentence?

What behaviour can we observe that allows us to categorize words as nouns? Looking at the inflectional morphology, we observe that most nouns in English have a singular and a plural form:

English uses a plural morpheme on a noun to indicate that there is more than one of something. But there is a subcategory of nouns that don’t have plural forms. Mass nouns like rice, water, money, oxygen refer to things that aren’t really countable, so the nouns don’t get pluralized. Nouns that refer to abstract things (such as justice, beauty, happiness) behave like mass nouns too. If they don’t have plural forms, why do we group them into the larger category of nouns? It’s because their syntactic distribution behaves like that of count nouns. Most English nouns, singular, plural, or mass, can appear in a phrase following the word the:

In their syntactic distribution, pronouns (I, me, you, we, us, they, them, he, him, she, her, it) do the job that noun phrases do. A pronoun rarely appears with the, but it can replace an entire noun phrase:

In Essentials of Linguistics, we’ll group pronouns into the larger category of nouns, remembering that they’re a special case.

Verbs behave differently to nouns. Morphologically, verbs have a past tense form and a progressive form. For a few verbs, the past tense form is spelled or pronounced the same as the bare form.

Adjectives appear in a couple of predictable positions. One is between the word the and a noun:

the red car

the clever students

the unusual song

the delicious meal

The other is following any of the forms of the verb be:

That car is red.

The students are clever.

The song is unusual.

The meal was delicious.

Many adjectives can be intensified with the words very or more:

very clever

more unusual

very delicious

And some adjectives (but not all) have comparative and superlative forms:

red – redder – reddest

smart – smarter – smartest

tall – taller – tallest

tasty – tastier – tastiest

The behaviour of adverbs is a little more difficult to observe. Unlike adjectives, adverbs don’t have comparative or superlative forms, but like adjectives, they can be intensified with very or more:

very quickly

very cleverly

more importantly

The above examples illustrate that many adverbs are derived by affixing -ly to an adjective, but there are also many adverbs that are not derived this way, and there are also some common English words that have the -ly affix that aren’t adverbs but adjectives, like friendly, lonely, lovely, so the affix is not a reliable clue. The syntactic distribution of adverbs is also a little slippery. Adverbs can precede or follow verbs (or verb phrases; see Unit 8.5) to provide information about the verb:

The children sang beautifully.

The students complained loudly about the pop quiz.

They had just arrived when the fire alarm rang.

Samira tripped and nearly broke her wrist.

The visitors will arrive tomorrow.

And adverbs can precede adjectives or other adverbs to provide information about the adjective/adverb:

This meal is surprisingly tasty.

An extremely expensive car drove by.

The children finished their homework remarkably quickly.

Because their behaviour is more variable than that of words in the other open-class categories, adverbs can be a challenge to identify. In the rest of this book, we’ll label adverbs as “A”, the same label that we use for adjectives.

The three syntactic categories of nouns, verbs and adjectives, are called open-class categories. The categories are considered open because when new words get added to the language, they are almost always in one of these three categories — the categories are open to new members. These categories are sometimes also called lexical categories or content words because these categories are the ones that do most of the lexical semantic work in a sentence: they convey most of the meaning of a sentence. The semantic content of the words from other categories (like the, of, in, that, etc.) is not as obvious as the semantics of the words from lexical categories.