A part of speech – are large lexico-grammatical classes of words differentiated on the basis of their semantic, morphological , syntactic propeties; (the grammatical category or word group in a language to which words may be assigned on the basis of how they are used in sentences. The traditional main parts of speech in English are noun, verb, adjective, adverb, pronoun, preposition, conjunction, and interjection.
The words of language, depending on various formal and semantic features, are divided into classes. The traditional grammatical classes of words are called “parts of speech”, since the word is distinguished not only by grammatical, but also by semantico~lexemic properties, some scholars also refer to parts of speech as lexico~grammatical categories (Смирницкий).
1. Noun
Meaning: thingness.
Form. Nouns have the category of number (singular and plural), though some individual nouns may lack either a singular or a plural form. They also, in the accepted view, have the category of case (common and genitive)
Function. (a) Combining with words to form phrases. A noun combines with a preceding adjective (big house), or occasionally with a following adjective (secrets unrevealed), with a preceding noun in either the common case (chocolate bar) or the genitive case (mother’s face), with a verb following it (children play) or preceding it (play games). Occasionally a noun may combine with a following or a preceding adverb (the guy outside; the then president). It also combines with prepositions (in a house; house of rest). It is typical of a noun to be preceded by the definite or indefinite article (the room, a room). (b) Function in the sentence. A noun may be the subject or the predicative of a sentence, or an object, an attribute, and an adverbial modifier. It can also make part of each of these when preceded by a preposition.
2. Adjective
Meaning. The adjective expresses property.
Form. Adjectives in Modern English are invariable. Some adjectives form degrees of comparison (long, longer, longest).
Function. (a) Adjectives combine with nouns both preceding and (occasionally) following them (large room, times immemorial). They also combine with a preceding adverb (very large). Adjectives can be followed by the phrase "preposition + noun" (free from danger). Occasionally they combine with a preceding verb (died young). (b) In the sentence, an adjective can be either an attribute (large room) or a predicative (is large). It can also be an objective predicative (painted the door green).
5. The verb
Meaning. The verb as a part of speech expresses a process.
Form. The verb is characterized by an elaborate system of morphological categories, some of which are, however, controversial. These are: tense, aspect, mood, voice, person, and number.
Function. (a) Verbs are connected with a preceding noun (children play) and with a following noun (play games). They are also connected with adverbs (write quickly). Occasionally a verb may combine with an adjective (married young). (b) In a sentence a verb (in its finite forms) is always the predicate or part of it (link verb). The functions of the verbals (infinitive, participle, and gerund) must be dealt with separately.
