The Structure of English Language - Word Classes

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We put words into categories or logical groups, according to how they work within phrases, clauses or sentences. These categories, traditionally called parts of speech are now more usually known as word classes. Parts of speech are labels for categories in which we usually place words. But in a given sentence a word from one category may behave as if it were in another. A dictionary will only record established or standard usage.

The traditional parts of speech were of eight kinds, excluding the two articles (a/an, the). These were

  • nouns,
  • pronouns,
  • adjectives,
  • verbs,
  • prepositions,
  • conjunctions,
  • adverbs, and
  • interjections.

Modern linguists prefer to list words in classes that are coherent - all the words in them should behave in the same way. But if this principle were applied rigidly, we would have hundreds of classes, so we allow irregularities!

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Closed and Open Word Classes

Some classes of words are called closed because they contain a relatively small number of items to which no new words can normally be added. These are the structural words, which include:

  • words (prepositions and conjunctions) which make connections (connectives or connectors),
  • pronouns and
  • words (including articles) like the, some, each that co-occur with nouns - these are called determiners.

Other classes of word are constantly being added to. Each contains a vast number of terms already. They are open to new words being introduced. The open classes are

  • nouns,
  • verbs and
  • the words which qualify them, adjectives and adverbs.

These form the bulk of a language's vocabulary or lexis (also lexicon, though this sometimes refers to a published version). These classes may be called lexical whereas the closed-class words are structural or functional. These tables illustrate the two kinds of word class.

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Closed Word Classes





A, the, any, my, those, which

She, them, who, that, himself

In, across, at, by, near, within

And, but, if, or, while, unless

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Open Word Classes





Abstract: fear, joy

Concrete: chair, mud

Common: boy, town

Proper: Fred, Hull

Transitive: bite, steal

Intransitive: live, cry

Modal: can, will, may

Auxiliary: be, have, do

Descriptive: lazy, tall

Comparative: lazier

Superlative: tallest

Manner: reluctantly, keenly, easily, softly

Time: soon, often

Place: here, there

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Problems of classification

Some words are difficult to classify. Not all grammatical descriptions will place them in the same word class. This, these or those are sometimes classified as demonstrative (or distinctive) adjectives or pronouns. Possessives, like my, his, their, are sometimes classified as pronouns (showing the word from which they are formed), sometimes as adjectives, showing their grammatical function of qualifying nouns: usually they are pronouns when alone (I like that) and adjectives when they precede a noun (I like this cupof tea). Traditional lists of adverbs contain words like very which qualify other adverbs or adjectives. This word class is sometimes called a “dustbin class”, because any word for which there is no obvious class will be put in it! Among words which have sometimes been classified as adverbs are the following: however, just, no, not, quickly, tomorrow and when.

This incoherence has long been recognized by grammarians who subdivide adverbs into further categories, such as adverbs of time, place or manner.

In trying to organize words into coherent classes, linguists will consider any or all of the following:

  • what they mean (semantics),
  • their form (morphology),
  • provenance (historical origin or derivation) and
  • function in a phrase, clause or sentence (syntax).

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Some words, such as numbers, do not fit in any of the word classes given above. They can behave as adjectives (one loaf or two?) or pronouns (I want one now!). And no one description of word classes is regarded as finally authoritative. Some classes (such as verbs or conjunctions) are fairly coherent. You should be able to discuss the problems of how or where to classify words which seem not to “fit”.

Also note that a dictionary does not (or should not) prescribe, but indicates the word class or part of speech where a word is usually placed. But in a given sentence, if the speaker or writer has used it as if it were in a different class, then this is where it should be placed.

For example, toilet is usually classified as a noun. But UK primary school teachers often speak of toileting children (I had to toilet John twice today). In describing such a sentence, you should be guided by the internal grammar of the sentence (syntax) rather than the dictionary. Here toilet is a transitive verb. If this usage becomes standard, lexicographers will record it. This kind of word formation is called conversion, a self-explanatory name.

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Every statement is a combination of words, and every statement says something to communicate information. The simplest possible kind of statement - for example, Dogs bark - has two kinds of words in it. It has a what word, dogs, and a what happens word, bark. These kinds of words are the most basic parts of any statement. If a person only says dog, no statement is made, and no information is conveyed. A sound is made that calls to mind a common, four-footed animal, but nothing regarding it is learned.

The what words are called nouns. They tell what is being talked about. They are identifying words, or names. Nouns identify persons, places, or things. They may be particular persons, places, or things: Michael Jackson, Reykjavik, World Trade Center. Or they may be general nouns: singer, town, building. Concrete nouns indicate things that can be seen such as car, teapot, and potato. Abstract nouns denote concepts such as love, honesty,and beauty.

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The what happens words are called verbs. They are the action words in a statement. Without them it is impossible to put sentences together. It is the verb that says something about the noun: dogs bark, birds fly, fish swim. Verbs are the important words that create information in statements. Although nouns alone make no statement, verbs can occasionally do so. Help! gives the information that someone is in trouble, and Go away! tells someone or something emphatically to leave.

Besides nouns and verbs there are other kinds of words that have different functions in statements. They are pronouns, adjectives, adverbs, conjunctions, articles, prepositions, and a very few words that can be called function words because they fit into none of the other categories. All of these kinds of words together are called parts of speech. They can just as well be called parts of writing because they apply to written as well as to spoken language.

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