summarise the text, give examples to approaches: The parts of speech are classes of words, all the members of these classes having certain characteristics in common which distinguish them from the members of other classes. The problem of word classification into parts of speech still remains one of the most controversial problems in modern linguistics. The attitude of grammarians with regard to parts of speech and the basis of their classification varied a good deal at different times. Only in English grammarians have been vacillating between 3 and 13 parts of speech. There are four approaches to the problem:

Classical (logical-inflectional)

Functional

Distributional

Complex

The classical (semantic approach) parts of speech theory goes back to ancient times. It is based on Latin grammar. According to the Latin classification of the parts of speech all words were divided dichotomically into declinable and indeclinable parts of speech. This system was reproduced in the earliest English grammars. The first of these groups, declinable words, included nouns, pronouns, verbs and participles, the second – indeclinable words – adverbs, prepositions, conjunctions and interjections. The logical-inflectional classification is quite successful for Latin or other languages with developed morphology and synthetic paradigms but it cannot be applied to the English language because the principle of declinability/indeclinability is not relevant for analytical languages.

A new approach to the problem was introduced in the XIX century by Henry Sweet. He took into account the peculiarities of the English language. This approach may be defined as functional(They distinguished between two classes of words:declinable (changeable forms) indeclinable (static forms:articles, prepositions)‏

He resorted to the functional features of words and singled out nominative units and particles. To nominative parts of speech belonged noun-words (noun, noun-pronoun, noun-numeral, infinitive, gerund), adjective-words (adjective, adjective-pronoun, adjective-numeral, participles), verb (finite verb, verbals – gerund, infinitive, participles), while adverb, preposition, conjunction and interjection belonged to the group of particles. However, though the criterion for classification was functional, Henry Sweet failed to break the tradition and classified words into those having morphological forms and lacking morphological forms, in other words, declinable and indeclinable.

A distributional (syntactic)approach to the parts to the parts of speech classification can be illustrated by the classification introduced by Charles Fries. The classification of words is based on the study of their combinability by means of substitution testing, which results in developing the standard model of four main “positions” of notional words in the English sentence: noun (N), verb (V), adjective (A), adverb (D)‏

He wanted to avoid the traditional terminology and establish a classification of words based on distributive analysis, that is, the ability of words to combine with other words of different types. At the same time, the lexical meaning of words was not taken into account. According to Charles Fries, the words in such sentences as 1. Woggles ugged diggles; 2. Uggs woggled diggs; and 3. Woggs diggled uggles are quite evident structural signals, their position and combinability are enough to classify them into three word-classes. In this way, he introduced four major classes of words and 15 form-classes. Let us see how it worked. Three test frames formed the basis for his analysis:

Frame A - The concert was good (always);

Frame B - The clerk remembered the tax (suddenly);

Frame C – The team went there.

As a result of those tests the following lists of words were established:

Class 1. (A) concert, coffee, taste, container, difference, etc. (B) clerk, husband, supervisor, etc.; tax, food, coffee, etc. © team, husband, woman, etc.

Class 2. (A) was, seemed, became, etc. (B) remembered, wanted, saw, suggested etc. © went, came, ran, lived, worked, etc.

Class 3. (A) good, large, necessary, foreign, new empty, etc.

Class 4. (A) there, here, always, then, sometimes, etc. (B) clearly, sufficiently, especially, repeatedly, soon, etc. © there, back, out, etc.; rapidly, eagerly, confidently, etc.

It turned out that his four classes of words were practically the same as traditional nouns, verbs, adjectives and adverbs. What is really valuable in Charles Fries’ classification is his investigation of 15 groups of function words (form-classes) because he was the first linguist to pay attention to some of their peculiarities.

All the classifications mentioned above appear to be one-sided because parts of speech are discriminated on the basis of only one aspect of the word: either its meaning or its form, or its function.

In modern linguistics, parts of speech are discriminated according to three criteria: semantic, formal and functional. This approach may be defined as complex. The semantic criterion presupposes the grammatical meaning of the whole class of words (general grammatical meaning). The formal criterion reveals paradigmatic properties: relevant grammatical categories, the form of the words, their specific inflectional and derivational features. The functional criterion concerns the syntactic function of words in the sentence and their combinability. Thus, when characterizing any part of speech we are to describe: a) its semantics; b) its morphological features; c) its syntactic peculiarities.

The linguistic evidence drawn from our grammatical study makes it possible to divide all the words of the language into:

those denoting things, objects, notions, qualities, etc. – words with the corresponding references in the objective reality – notional words;

those having no references of their own in the objective reality; most of them are used only as grammatical means to form up and frame utterances – function words, or grammatical words.

It is commonly recognized that the notional parts of speech are nouns, pronouns, numerals, verbs, adjectives, adverbs; the functional parts of speech are articles, particles, prepositions, conjunctions and modal words.

The division of language units into notion and function words reveals the interrelation of lexical and grammatical types of meaning. In notional words the lexical meaning is predominant. In function words the grammatical meaning dominates over the lexical one. However, in actual speech the border line between notional and function words is not always clear cut. Some notional words develop the meanings peculiar to function words - e.g. seminotional words – to turn, to get, etc.

Notional words constitute the bulk of the existing word stock while function words constitute a smaller group of words. Although the number of function words is limited (there are only about 50 of them in Modern English), they are the most frequently used units.

Generally speaking, the problem of words’ classification into parts of speech is far from being solved. Some words cannot find their proper place. The most striking example here is the class of adverbs. Some language analysts call it a ragbag, a dustbin (Frank Palmer), Russian academician V.V.Vinogradov defined the class of adverbs in the Russian language as мусорная куча. It can be explained by the fact that to the class of adverbs belong those words that cannot find their place anywhere else. At the same time, there are no grounds for grouping them together either. Compare: perfectly (She speaks English perfectly) and again (He is here again). Examples are numerous (all temporals). There are some words that do not belong anywhere - e.g. after all. Speaking about after all it should be mentioned that this unit is quite often used by native speakers, and practically never by our students. Some more striking examples: anyway, actually, in fact. The problem is that if these words belong nowhere, there is no place for them in the system of words, then how can we use them correctly? What makes things worse is the fact that these words are devoid of nominative power, and they have no direct equivalents in the Ukrainian or Russian languages. Meanwhile, native speakers use these words subconsciously, without realizing how they work.
The text discusses the classification of parts of speech and the different approaches to this classification. The classical approach, based on Latin grammar, categorizes words into declinable and indeclinable parts of speech. The functional approach, introduced by Henry Sweet, categorizes words based on their functional features and distinguishes between declinable and indeclinable words. The distributional approach, introduced by Charles Fries, classifies words based on their combinability in sentences. The complex approach, used in modern linguistics, discriminates parts of speech based on semantic, formal, and functional criteria. Notional parts of speech include nouns, pronouns, numerals, verbs, adjectives, and adverbs, while function words include articles, particles, prepositions, conjunctions, and modal words. However, the classification of adverbs remains controversial and some words do not fit into any specific category.
give examples to each approach
Examples for each approach to the classification of parts of speech:

1. Classical (logical-inflectional) approach:
- Declinable words: nouns (e.g. cat, dog), pronouns (e.g. he, she), verbs (e.g. run, eat), participles (e.g. running, eaten)
- Indeclinable words: adverbs (e.g. quickly, slowly), prepositions (e.g. on, in), conjunctions (e.g. and, but), interjections (e.g. oh, wow)

2. Functional approach (Henry Sweet’s approach):
- Declinable words: noun-words (e.g. cat, dog), adjective-words (e.g. big, happy), verb (e.g. run, eat)
- Indeclinable words: adverbs (e.g. quickly, slowly), prepositions (e.g. on, in), conjunctions (e.g. and, but), interjections (e.g. oh, wow)

3. Distributional (syntactic) approach (Charles Fries’ approach):
- Noun: concert, coffee, taste, container, difference
- Verb: was, seemed, became
- Adjective: good, large, necessary, foreign
- Adverb: there, here, always, then

4. Complex approach (modern linguistics):
- Notional parts of speech: nouns (e.g. cat, dog), pronouns (e.g. he, she), numerals (e.g. one, two), verbs (e.g. run, eat), adjectives (e.g. big, happy), adverbs (e.g. quickly, slowly)
- Function words: articles (e.g. a, the), particles (e.g. up, down), prepositions (e.g. on, in), conjunctions (e.g. and, but), modal words (e.g. can, will)

Note: The examples provided are just illustrative and there are numerous other words that fall under each category.
простыми словами и с примерами объясни разницу между morpheme morph and allomorph
Morphemes are the smallest units of meaning in a language. They are like building blocks that make up words. For example, in the word “cats,” there are two morphemes: “cat” (referring to the animal) and “-s” (indicating plurality).

A morph is a specific form of a morpheme. It is the actual realization or expression of a morpheme in a word. For example, the morpheme “-ed” can have different forms (“walked,” “talked,” “played”) in different words, but they all carry the meaning of past tense.

Allomorphs, on the other hand, are different versions or variations of a morpheme. They can exist due to phonological or grammatical rules in a language. Allomorphs of a morpheme represent different ways the morpheme can be pronounced or written, while still conveying the same meaning. For example, the plural morpheme “-s” has different forms (“-s,” “-es,” “-ies”) depending on the specific sound or letter that comes before it in a word: cats, boxes, puppies.

In simple terms, a morpheme is the smallest meaningful unit, a morph is the specific form of that morpheme in a word, and allomorphs are the different versions of a morpheme that can be used based on specific rules in a language.
Simple sentences consist of two structures a surface one and a deep one

The surface structure is a set of function-expressing positions filled with such parts of the simple sentence as the subject, the predicate, the object, the attribute and the modifiers.

The parts are arranged in a hierarchy, so we distinguish the main and the secondary parts of the simple sentence.

The basis of the surface structure — the reflection of some situational event.

The deep structure is an abstract model of some syntactical relations between defined by the valency of the finite verb. So, actually we may see under the deep structure the relations between the finite verb and its arguments. Some of the relations are obligatory (according to the valency) and some are optional. They distinguish some parts of the deep structure as well (Appendix1)

7.2.1. The surface structure of the simple sentences. The Subject. The Predicate. The Secondary parts of the sentence.
The notional parts of the simple sentence each occupying a notional position in it, are subject, predicate, object, adverbial, attribute, parenthetical enclosure, addressing enclosure; a special, semi-notional position is occupied by an interjectional enclosure. The ultimate and highest object of this integral modification is the sentence as a whole, and through the sentence, the reflection of the situation (situational event).

Thus, the Subject is the main part of a sentence, presenting the doer of the action or the object determined by some properties or states, a person-modifier of the predicate. Usually expressed by the nouns, taken in its nominative case, substantivised pronouns(I, he, someone) numerals(the two, the five), and also substintivised adjectives(the blind, the poor), the gerund (his arriving), infinitive(to read is his passion), etc.

The Predicate is is the main part of a sentence, describing the property of the object(or subject-person), presented by the Subject. a process-modifier of the subject-person. The Predicate is the source of predicativeness in a sentence what distinguishes a sentence from a word and word-combination. The Predicate makes up the functional minimum of a sentence. Usually expresses grammatical categories, characterizing the sentence as it is suggestion (the category of mood, tense, voice). Being a communicative centre of a sentence, the Predicate formally depends on the Subject correlating with it in number and person. They distinguish two types of the Predicate: 1) the simple (notional) and 2) compound (compound verbal and compound nominal ) predicate.

The Object is the secondary part of a sentence which expresses the object of the action, a substance-modifier of a processual part (actional or statal). It is usually to determine the Predicate. If the Predicate is presented by transitive verb, the object is used to specify the direction of the action expressed by the verb. . Describing the same situation of the reality , a verb can be oriented on the different “participants”(cf. to unload the coal from the carriage and to upload the carriage).

The Adverbial modifier the secondary part of a sentence, expresing the second properties of the action or the state presented by the verb(place, time, purpose, manner, reason, etc), a quality-modifier (in a broad sense) of a processual part or the whole of the sentence (as expressing an integral process inherent in the reflected event). Usually expressed by the adverb. As the averbial modifiers may be seen verbal adjectives, objective cases of the nouns and the infinitive. The adverbial modifier may characterise either the whole sentence or the separate word. The adverbial modifiers are the least dependent parts of sentence. In the cases when the adverbial modifiers ( especially taken in the temporal or local meaning ) are closely related to the lexical meaning of the Predicate, they may overlap with the objects.

(for example to arrive in a city – the defining in a city will depend on the question asked If it is in what question, this word-combination will be seen as the object and if it is where –question, it will be the adverbial modifier of place.)

The substantial difference between the adverbial modifier and the object may be seen in the fact that each type of the object corresponds to one specific syntactic position opened by the peculiar verbal governing which allows the usage of the names with coordinating connection only "I read these books. At the same time the adverbial modifiers may correspond to several syntactic positions — In summer, from the end of July to the end of August I was having rest in the resort house, on the Black sea.

The Attribute is the dependent secondary part of sentence, a quality-modifier of a substantive part. It is grammatically connected to the defined noun and is designed to indicate the property of the described object. Except the nouns the attributes may define other parts of sentence like the Predicate (nominative predicative). Closely connected with the adverbial modifiers of manner expressing the property of the process described by the Predicate. (to run quickly –a quick run; to act hastily – a hasty act)

The parenthetical enclosure is a detached speaker-bound modifier of any sentence-part or the whole of the sentence. The addressing enclosure (address) is a substantive modifier of the destination of the sentence and hence, from its angle, a modifier of the sentence as a whole. The interjectional enclosure is a speaker-bound emotional modifier of the sentence.

The first structural division divides the sentence into two phrases connected by predicative relations – the nounal phrase and the verbal phrase.

Each part of the sentence contains the nucleus, grammatically important components —the Subject and the Predicate, seen as the main parts of sentence. They determine formally-grammatical organization of a sentence. Other parts of the sentence are considered to be secondary.

The Subject part of subject corresponds to the subject of judgement and the theme of report.

the Predicate part- to the predicate of judgement and the rheme of report.

Thus, for the constituents of a sentence are characterized primary both by logical and communicative function.

The predicate part is presented by the objects and the adverbial modifiers. Additions are connected with the verb(rarer with the adjective or the noun)

The syntactic functionality of parts of speech is not equal. So the largest syntactic functionality is typical for the nouns (which may play different syntactic roles in a sentence) . And it is much less when concerns the adjectives and the verbs (as the verbs the Predicate only and the adjectives either the attribute or the nominal predicative).

The structural scheme of a sentence is an abstract syntactic standard of the separately taken simple sentence. The syntactic order of language is the set of regularities responsible for the construction of syntactic units.

summarize the text and answer what is simple sentence