Why do we need one-piece sentences?

A characteristic feature of a one-part sentence is the presence of only one main member of the sentence in a grammatical basis - subject or predicate. This main term calls an action, phenomenon or object, and also expresses their relationship to reality. Thus, the predicativity necessary for each sentence is created, i.e. expression by language means of this relation.

The issue of the syntactic nature of some single-component sentences is still controversial among linguistic scholars. However, in the school course of the Russian language in the form of a grammatical basis, it is customary to distinguish nominal, definitely personal, generalized personal, indefinite personal and impersonal sentences.

A nominative (nominative) sentence expresses the presence, existence of an object or phenomenon, i.e. has existential significance. The main member of this type of one-component sentences is the subject, which is expressed by the noun, personal pronoun, and also a quantitative-noun combination. (Morning. Here it is, Fatherland! Eight hours.) Since the sentence is built without a verb, it always has the meaning of the present tense and expresses the event that occurs “in front of the eyes” directly. Such sentences are often used in literary texts, especially in poetic speech. ("Night, street, lantern, pharmacy. / Meaningless and dim light." A.A. Blok)

A certain-personal sentence expresses an action performed by a certain person - the speaker or the interlocutor. Since the main term - the predicate - is expressed in the form 1, 2 persons of the verb in the indicative mood or 2 persons in the imperative mood, these sentences do not need a pronoun, because in the predicate form, an indication of a specific person has already been concluded. (Do you want some tea? I’m walking in the field, admiring the sunset.) These sentences are similar in structure to personal two-part sentences and are often used in lively conversation. Actualization of the subject of action is achieved by using treatment. (I hope Victor, to find you at this place.)

An indefinite-personal sentence expresses an action that is not related to a specific person (actor), although it is thought of as being committed by someone. The predicate, expressed by the form of the verb 3 of the plural in the present or future tense, the form of the plural verb in the past tense, allows you to focus on the nature of the activity, and not on the subject of the action. Most often, this type of sentence is used in colloquial and artistic styles and is practically not used in scientific and business, where accuracy and utmost clarity of expression are necessary. (They sing along the river. There was a knock on the door.)

A generalized-personal sentence expresses the action of a generalized, but not named person. The grammatical forms of the predicate are the same as in certain personal and indefinite personal sentences, with the exception of past tense forms and 1 person forms. The main role of generalized-personal sentences is the figurative expression of judgments, often embodied in proverbs, aphorisms. ("Do you like to ride - love and carry a sleigh"; "They don’t pay for insulting money.")

An impersonal sentence expresses an action or condition that is not associated with a person, object (actor). The grammatical basis consists of a predicate expressed by an impersonal verb or words of the category of state. (It really got sick. It was terrible to remain in the dark.) Also, sentences with denial have an impersonal form. (There was no wind. There is not a cloud in the sky.) Impersonal sentences can indicate the state of nature, the environment; condition of a living being; emotional or moral-ethical assessment of an action called an infinitive. The stylistic possibilities of impersonal sentences are unusually wide; they are especially often used in artistic speech. ("Unfortunately, it is impossible to write a story of things." KG Paustovsky)