PART OF SPEECH THEORY
All the words are subdivided into groups which have common features, principles. Such principles of division have been known since a very long time ago. In Russian linguistics the principles were formulated by Pr.L.V. Shcherba.
These principles are: meaning, form, function, form-building elements.
A part of speech is a group of words which have the common meaning, form, function, word-building elements.
By meaning we understand an abstract lexical meaning common to the words of the class. They are: the meaning of substance, things for nouns; the meaning of property for adjectives; the meaning of process, action or state for verbs; the meaning of number for numerals; the meaning of indication for pronouns; the meaning of property for adverbs.
By form we mean common grammatical categories and they are number and case for nouns; the degree of comparison for adjectives; the special form of composition for compound numerals and ordinal numerals; case for personal pronouns; person, number, tense, aspect, voice, mood for verbs; degrees of comparison for some adverbs.
By function we mean the ability to connect with words of other parts of speech and perform the syntactic role of words in the sentence typical of a part of speech. They are: the substantive functions (subject, object, predicative) for nouns; numeral attribute and numeral substantive for numerals; substantival and adjectival for pronouns; the finite predicate for the finite verb and other than verbal for non-finite verbs; adverbial modifier for adverbs.
Every part of speech has common word-building elements (suffixes, prefixes) by which we recognize one part of speech from another ("ion" — noun suffix, "teen"- numeral suffix, "al" — adjective suffix, "ize" — verb suffix etc.).
The role of each criterion of parts of speech is not the same. The semantic criterion is very important for all the languages. For example, "to work" — "a work": both express process, but "to work" preserves the meaning of process, it is considered to be a verb, while the process expressed by "a work" is understood as a substance, that is why "a work" is a noun.
For languages with a highly developed morphemic system the form or morphemic criterion is the most important (as in Russian).
For languages with a poor morphemic system the syntactic function has the most important role (as in English). But all the criteria should be taken into consideration.
The number of parts of speech is different in various linguistic schools. Russian linguists name the following parts of speech in English grammar (Pr. Khajmovich's point of view):
1) nouns,
2) pronouns, 8) modal words,
3) adjectives, 9) prepositions,
4) numerals; 10) conjunctions,
5) verbs; 11) particles,
6) adverbs, 12) interjections,
7) adlinks or statives (such words 13) articles,
as asleep, afraid, aware, etc.), 14) response words (yes, no).
Parts of speech can be subdivided into smaller lexico-grammatical subclasses. The subdivision will be based on the same principles which we use to define parts of speech. Parts of speech can be notional and formal (or functional).
Notional parts of speech (from #1 to #7) denote distinct lexical meaning and perform independent, syntactic function in the sentence. They have certain grammatical categories; they are changeable words in English vocabulary, they can be connected with each other directly or with the help of the formal words.
Contrasted against the notional parts formal words are words of incomplete nominative meaning and don't perform any independent functions in the sentence.
Some linguists refer modal words, interjections and words of affirmation and negation (or response words) as a special group of independent elements because they have a peculiar meaning. They express modality (human's attitude of the speaker to the situation, human emotions, feelings, affirmation or negation. They are not connected with any particular word in the sentence. Modal words (perhaps, sure, probably etc.) are considered to be referring to the sentence as a whole. Interjections (oh, alas) and words of affirmation and negation can make a sentence themselves.
Prepositions, conjunctions, particles (to, just, only, not, no) and articles are called formal or functional parts of speech. Some linguists say that they are formal because they have no lexical meaning of their own. But if those words had no lexical meaning of their own, they couldn't be called words at all. Any word is a word because of its lexical meaning. Those words have lexical meaning, but it is peculiar. They express an extra linguistic phenomenon: relation, connection. The article expresses the specific limitation of the substantive functions. Prepositions denote relations between notional words, conjunctions express connection between them. Particles have specifying and limiting meaning. Formal words morphologically are unchangeable words, they can't make a sentence without notional words, nor can they perform any particular functions in the sentence.
THE NOUN
The noun is a group of notional words with a common abstract, thingness meaning which have grammatical categories of number, case, lexico-grammatical category of gender. The noun is connected in the sentence with other nouns, verbs, adjectives, seldom with adverbs (the then president), prepositions, pronouns and etc. The noun performs all functions in the sentence except the function of a predicate. The peculiar feature of English nouns is that they can perform the function of a prepositional attribute without any changes in form (a stone wall, the sea breeze).
Structurally the noun can be simple (the sky), derived (brotherhood) with suffixes, compound — with two roots (raspberry), composite — with two or more words (brother-in-law, pain-killer) and abbreviation (A.A. — American Army, p.m. and etc.). According to the meaning and certain grammatical properties the noun can be proper (Mary, Monday, London) and common. Common nouns can be collective (people, police, gentry, family), material (iron, paper), abstract (sadness, tight). The nouns can be animate (cat) and inanimate (chair), human (girl) and non-human (cat).
The category of number of the Noun
This category shows if we mean one or more, than one thing or person. It is expressed by the opposition of the singular (the zero inflexion) to the plural form (-es inflexion) which is represented in speech by its allomorphs ([z], [s], [iz]).
The other, non-productive ways of expressing the number opposition are with the help of inner inflexion (sound alternation: man — men) or with the help of the suffix (e)n (child — children, ox —- oxen), one more way is with the.help, of a limited number of a special inflexion of borrowed nouns (phenomenon — phenomena, formula — formulae), In some cases the plural form is homonymous with the singular form (sheep, deer, swine, fish).
But there are two types of nouns which have only one form of number, which belong to the so-called uncountable nouns. Two subclasses of uncountable nouns are usually regarded as singularia tanlum (only singular) and pluralia tantum (only plural).
Singularia tantum has only a singular form, such nouns denote material substance (milk) or abstract notions (peace). Singularia tantum excludes the use of the modifying numeral "one", the indefinite article. They are modified by a finite verb in the singular form.
If singularia tantum has the ending -es, it means that they have changed their lexical meaning (water — waters, beauty — beauties). Some of them have the ending -es without the indication of the plural number. They can denote the names of science (physics), of game (dominoes). They are modified by a verb in the singular form.
Pluralia Tantum cannot directly combine with numerals and only occasionally with words "many, few" and take the finite verb in the plural form. They denote objects consisting of two halves (trousers, scissors, spectacles), some sort of collective meaning (outskirts, clothes, police, people, gentry [благородное сословие, люди]), some proper names (Middlands, Downs).
Some collective nouns -can be pluralia tantum or singularia tantum accordingly, due to that they are associated with. If such collective nouns as family, group, jury, government denote the notion of integrity, they are understood as the noun in the singular and substituted by the pronoun "it" and associated with the verb singular (The jury consists of 12 members). If they denote the comprising parts of the unity, they may be understood as nouns in the plural and substituted by the pronoun "they" and associated with the verb plural. (The jury are divided concerning the verdict).
There is a problem of lexicolization of the category of number. In some cases the ending -es becomes the suffix with the ability to change the meaning of the word (authority — authorities, picture — pictures).