Contextual semantic functions of the nuclear sentence patterns in expending the communicative intention of the speaker and ways of their teaching

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. 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. and The bread and cheese was presently brought in and distributed [...] . 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 who've left your wife.
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 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. 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.
The sentence as a main syntactic unit performs the function of predication. The basic predicative meanings are expressed by the finite verb which is connected with the subject of the sentence. This predicative connection is referred to as the predicative line of the sentence. Depending on their predicative complexity, sentences can feature one predicative line or several predicative lines, respectively sentences can be "monopredicative" and "polypredicative".¹⁰ Under this distinction the simple sentence is a sentence in which only one predicative line is expressed, e.g.: We have much in common. It is raining. In respect of predication a proper simple sentence should be distinguished from a semi composite sentence or complementational sentence and clause-conflational sentence. Semi-composite sentence can include, for example, homogeneous sentence-parts: either subjects or predicates, which represent polypredicative structures¹¹. It is quite evident that the sentences express two different predicative lines: in the first one the two subjects form separate predicative connections and in the second one the two predicates are separately connected with the subject. Semi-composite sentences, as well as complementational sentences, can also include a clause which functions as the subject or the object of the verb, e.g.: I saw them break into the house. To finish it in time was impossible. Clause-conflational sentences, as termed by L.Talmy, are syntactic units which are based on clause fusion. They represent conceptual complex and therefore possess polypredicative structures, though on the formal syntactic level appear as simple sentences. Such like structures are probably based on a higher degree of conceptual integration between parts of an event complex, as compared to semi-composite or complementational sentences, e.g.: The leaves withered away. These cars are expensive to repair. Representation of polypredication is conditioned by interaction of lexical semantics of sentence elements and a particular type of syntactic construction. Thus, we may state, that a proper simple sentence, or a single-clause sentence, to put it more exactly, is a monopredicative unit, as distinguished from composite and semi-composite sentences (complementational and clause-­conflational sentences in terms of cognitive approach). Traditionally the investigation of structure of the simple sentence and its constituents is performed in 'terms of sentence-parsing. Sentence-parsing scheme presupposes that a sentence is organized as a system o(function-expressing positions. The content of the functions reflects a situational event. The function-expressing positions are viewed as parts of the simple sentence, which are subject, predicate, object, adverbial, attribute, parenthetical enclosure, addressing enclosure and interjectional enclosure. The parts are arranged in a hierarchy, all of them perform some modifying role: