The parts of the sentences are the basic syntactical units. First and important in the investigation of the structure of the sentence is segmentation that is articulation of the composition of the sentence into constituents.

A sentence as a unit of the language, with the help of which speech communication is carried out, must reflect, on the one hand, all diversity of possible, constantly changing beyond the language situations and, on the other hand, regulate the imagination of them through generalizing character structural schemes and semantic configurations.[1] Only satisfying these requirements the language can effectively function as a means of communication and a means of thinking activity of man. It is natural that a member of the sentence as a constituent part of the sentence cannot be indifferent to these requirements, but on the contrary, must provide their implementation.

The part of the sentence when it functional syntactical nature doesn’t change in all unlimited number of the real sentences (the subject as a source or the object of the action, the predicate as an action that the subject carries out) being differently expressed lexically under conditions of identity of lexemes is sorted as a component of each new sentence with all the new subjects, with their properties, their terms of existence, thus providing the reflection of final setting of language means of unlimited diversity of the objective world and worlds that are created by intellectual activity of human being.

Part of the sentence is a two-sided language mark, which possesses the meaning and the form.

Its meaning is syntactic function, that is, that substantial relation, in which given syntactic element is in another structure of some syntactic consecution of elements. The form of the part – is not only syntactically meaningful morphological form of the word, but also characteristics, connected with the belonging of the word to the definite part of speech or to the category of words inside of the part of speech, presence or absence of secondary auxiliary words, the location in the relation to another element, intonation indications of syntactic relation- shortly everything that allows to identify the word or group of words as a bearer of definite syntactic- functional significance. Thus, syntactic form, unlike morphological one, is multi- componential.

The diversity of syntactical and semantic configurations is unlimited.

The system of the parts of sentence in some extent is appropriate to the system of parts of speech. What elements form the system of parts of the sentence? Their nomenclature is standard and therefore it unlikely needs the substantiation. These are the subject, the predicate, the object, the modifier and the attribute. Full parallelism between that and the other systems is not only undesirable from the point of view of substantial problems and the possibilities of the language, but also on principle it is impossible, even for the fact that in the structural-semantic nature of some parts of speech are input their syntactical half-functionality. Thus, the noun as a expresser of the meaning of the object can be the subject, the object, the modifier, nominative attribute, nominative part of the predicate.

Traditionally the parts of the sentence are divided into main and secondary parts. Taking the given designations as conditionals (such-called secondary parts, like the main parts can belong to the structural minimum of the sentence; the object is correlative with the subject) one should acknowledge that established division traditionally reflects the necessary differential property of the parts of the sentence, and especially their participation / absence in the formation of predicative core of the sentence, in expressing the category of predicativity. Practical convenience to the advantage of such division is in its unambiguity: the subject and the predicate are the main parts of the sentences; the others are always secondary parts of the sentences.

If to proceed from the role that the parts of the sentence play in formation of structural-semantic minimum of the sentence, then it turns out that most of the objects and some modifiers (depending on syntagmatic class of the verb-predicate ) are the as important as the subject and the predicate. The removal of the objects and the modifiers in the examples below makes them grammatically and semantically unmarked:

She closed her eyes. (D. Lessing) She was there. (I. Murdoch)

The distribution of the parts of the sentence will be different if they are considered coming from the role in the actual articulation of the sentence.[2] Here it appears that it is secondary parts that are communicatively essential (rhematic), as the subject and to the less extent predicate form initial part of the utterance (thematic). In the following example But she cries always in the succession of the sentence She doesn't move for hours at a time. But she cries always.' (S. Maugham) the modifier always forms more important part of the information, given by this sentence, than the subject.

Thus the elements of one and the same system are organized differently, if they are considered in the aspects of different properties peculiar to them.

It will be right in establishing the systems of the parts of sentence to come from the roles of parts of sentences in the formation of the sentence and from the character of their mutual relations. Here we can distinguish three main groups of the parts of the speech:

The first group includes the subject and the predicate. The status of the subject and the predicate is special in comparison with the other parts of the sentence. Only the subject and the predicate are mutually connected with each other and independent in the relation to any other member of the sentence as all the other parts can be raised on the base of the ties of dependence on the subject and the predicate as topping elements. This hierarchy of dependence is clearly seen when establishing the schemes of dependence. The top layer is occupied by the subject and the predicate. Look at the scheme of dependence for the sentence Small white crests were appearing on the blue sea (in it interdependent elements are connected with reciprocally directed pointer, topping and dependent elements- one- side- directed pointer from the dependent to the topping element[3].:

The second group includes the object and the modifier. The object and the modifier are the invariably dependent parts of sentence. They can verbally-oriented, i.e. syntactically they usually depend on the verb (The object can depend on the adjective in the predicative position): I am very bad at refusing people who ask me for money. (I. Murdoch)- Mendan pul so’raganlarga men yo’q deyolmayman. the objects and the modifiers can be completive, i.e., the elements which are important for structural-semantic completeness of elementary sentence. Compare the impossibility to omit both of these parts of the sentence in the sentence: She treated Daddy like a child, [...] (A. Wilson).- U dadasiga huddi bolaga qaraganday muomala qilardi.

The third group includes the attributes. Always dependent, like the objects and the modifiers, the attributes, in contrast to those parts, syntactically connected only with the nouns. Their non- verbal orientedness determines their belonging to the different cut in the articulation of the sentence. In contrast to al these elements attributes are not included in the structural scheme of the sentence.

The problem of substantiating differentiation of the parts of speech remains complex one. It is relatively easy solved in differentiation of main and secondary parts of the sentences. Only by first one the category of predicativity is expressed, but the second one does not participate in its expression. When there is a verbal predicate, the differentiation of the subject and the predicate is carried out on the base of indication of morphological nature of words: name — the subject, verb — predicate. In case the predicate is nominative with the noun as a nominative part, it will be difficult to solve the question what is. It also can be inversed location of the subject and the predicate.

The status of the subject and the predicate in the structure of the sentence is unique. Only with the help of them the category of predicativity is expressed, which is the most important structural and semantic indication of the sentence. Strictly speaking, the predicativity is expressed by the forms of the verb-predicate. But, however, these forms themselves arise and exists on the base of unity and at the same time on mutual contraposition of the subject and the predicate, it can be said about the participation, let it be indirect, of the subject in expressing the category of predicativity.

Mutual relationship of these two members of the sentence is also unique. In combination of the subject and the predicate there are not dominant and dependent elements. The subject and the predicate are in the interdependent realtion.

At the same time all other parts of the sentence directly or indirectly are connected with the subject and the predicate by the tie of dependence.

That’s why the first and the foremost articulation of the sentences on immediate constituent parts, which takes into account the relations of syntactical dependence is the division into the groups of subject and the group of predicate (the group of nouns and the group of verbs). The subject and the predicate are the only parts of the sentence among other parts of the sentence which are permanently included into structural-semantic minimum of the sentence. In English one can come across verbal sentences of two-part type.

In imperative sentences there is not subject, but it is given in implication. This is the subject you. It is reality is proved by constructing the imperative type with explicit subject, for example: You stay at home! and also is confirmed by transformative analyses of imperative sentences with reflexive forms of the verb: Wash yourself!

The subject. The subject is syntactical counter-part and simultaneously “the partner ” of the predicate. The subject fulfills two structural functions in the sentence:

1. categorical function

2. relative function.

Categorical function of the subject includes designation of the bearer of the predicative feature, conveyed by the predicate. Compulsory two-partness of the English verbal sentence makes the subject essential constituent element of the sentence.

Relative function of the subject consists of the fact that it is initial element in consistent sintagmatic unfolding of the sentence, forming left-sided encirclement of the verb-predicate, which withstands to its right-sided encirclement, first of all to the object or to the objects. As a part of the sentence sui generis the subject is formed only when there is the predicate. In the absence of the latter the word form of nominative case of personal pronoun or common case of the noun is not enough to ascribe the status of the subject to the appropriate words.

On the other hand, quantitative meaning of the noun-subject (not its form) determines the form of the verb as a predicate or its changing part in the relation of the number. In the singular form (but the meaning of partitioned majority) of the subject the predicate takes plural form. On the contrary in the plural form (by its meaning unpartitioned majority) or the plurality connected with coordinating conjunction of the nouns and the group of subject interpreted by language perception as a single referent, the predicate takes the singular form. Comp.: The staff were very sympathetic about it. (A. J. Cronin) – Hamkasabalar bu haqida achinishdi. and The bread and cheese was presently brought in and distributed [...] (C. Brontë).- Non va pishloq sovg’a sifatida olib kelindi va tarqatildi. One more indication of primary importance of real, but not formally marked content of the subject (in the subject itself) is the choice of ways of sequence between the subject and the predicate in person in the cases when the person of the subject does not have differentiated expression: 'Then it's not your wife who left you; it's you w h o'v e left your wife.¹ (S. Maugham)- U holda tashab ketgan sening hotining emas; bu faqt sen hotiningni tashlab ketgan.

The object. One of the distinguishing peculiarities of the object (in contrast to the modifier) with especially clear and consistent manifestation in English is its correlation with the subject. In general, both parts of the sentence has in morphological- lexical plan common substantive base, can be in the relations of conversion (X played Y ↔ Y was played by X). The object can be easily transformed to the subject in the passive form of the verb in the sentence. In verbal sentences the subject and the object are the closest (according to the character of syntactical connections) to the verb elements of its encirclement. The object which is in syntactical ties with the verb-predicate is invariable component of the structural scheme of the sentence. The appearance of the object in the sentence, as a rule, is determined by the semantics of the verb or the adjective in predicative use. That’s why the object is characterized by limited distribution.

The object does not possess such single structural meaning as the subject. In contrast to other parts of sentence, the classification of which is lightened by morphologization and lexicalization of appropriate syntactic meanings, the objects do not have such lexical-grammatical correspondences.

One of the common classifications of the objects in English is their division into direct, oblique, and prepositional objects.

Modifier. The modifier does not transform into the subject. Its presence in the sentence is not always determined by the semantics of the verb, and that’s why, being free in the possibilities of use, modifier can be present in any type of the sentences. Therefore the modifier can be characterized as the member of the sentence which possesses free distribution. Only in the connection with the limited number of the verbs, and especially the verbs which have adverbial direction, the modifier is the component of structural scheme of the sentence.

As to morphological- lexical base, modifiers have broader than the objects do. It includes not only nouns, but also adverbs, participles.

Attribute. In contrast to the parts of the sentences spoken above, that is the subject, the object, the modifier, which can be or full are verbal-oriented in the relation of syntactical ties, the attribute is substantially- oriented. The attribute is the dependent element of nominative word expression, denoting attributive feature of the object, called noun. It is important to reveal the distinguishing features of the attribute in comparison with the predicate, because both of them denote the feature of the object. The predicate, in contrast to the attribute denotes predicative feature. Besides the attribute is an element of the phrase. But the subject and the predicate do not form phrases. And finally, when the predicative feature can be put in the connection with the noun in the position of the subject, the attribute can join the noun in any syntactical function.