III. MAJOR FEATURES OF THE SENTENCE

1. PREDICATIVITY 

In the sentence is a syntactic category that is the means of expressing a thought. Predicativity has nothing to do with the relation between the sentence and reality. Predicativity is a structural feature of the sentence and is the backbone of human thinking and linguistic statements. Simply, it means 'saying sth about sth ' ; it comprises relation of dependence between two members - one member which is what the statement is about, which is subjected to description (the subject) and another member which predicates sth about the Subject, which describes the Subject, ascribes features and characteristics to the Subject.
E.g: The sky is blue.
'the sky' is what the sentence is about (Subject) and 'is blue' is the Predicate characterizing the Subject. Predicativity is binary relation(S-P); The Subject and the Predicate are correlative notions - a Subject functions only in correlation to a certain Predicate and vice versa.

The predicate relation is different from the attributive relation - only the former expresses a thought, statement, whereas the latter is like a label of some entity or phenomenon.
cf. nice house - attributive expression, 'label' of some house;
The house is / could be / must have been nice. - predicative relation, expresses a thought / statement about the house.

According to Reformatskiy, predicativity is the main relation in the sentence; it is the nucleus, the basis of communication. The predicative relation corresponds to an act of thinking. In this act the subject of thought combines predicatively with its characteristics. This act of combining a subject with a predicate /two notions/ results in a thought. In the real world objects and their features are not separated, which can be illustrated with the so-called attributive word combinations like: blue sky, white clouds. Human reasoning singles out the separate components of reality and then relates them to each other predicatively as a subject and predicate,

E.g.: The sky is blue. The clouds are white.


 The subject resides in space, whereas the Predicate relates to time and thus the Subject-Predicate relation forms a static-temporal framework which captures the two basic dimensions of the physical world. It should be noted therefore, that predicativity relates closely to space and time and one of the most succinct definitions is that of Agayan: “Predicativity is relating features and characteristics to an object in space and time.”
Predicativity should not be identified with the verb alone, although the latter plays a central role. Predicativity can also be expressed through intonation, the dialogue situation, the context, some modal and prosodic / rhythm and melody / means.

2. MODALITY 

is another major feature of the sentence. It should be distinguished from predicarivity because modality is not a structural but a semantic feature. Modality refers to the relation between a statement and reality, i.e. whether a certain fact really exists or is merely regarded as possible, imaginary, desirable etc. Modality is normally expressed through the linguistic category mood or modal words.

3. INTONATION. 

Being a unit of speech, the sentence has another important feature: it is intonationally delimited. Intonation separates one sentence from another in the continual flow of speech. It also participates in rendering essential communicative meanings, such as the syntactic meanings of interrogation, exclamation etc. Intonation is a major difference between sentences and the words and phrases outside the sentence.

E.g: Word / phrase                                               sentence
            water                                                      Water! Water?
        cold water                                                   Cold water! Cold water?

The words and phrases in the given examples are simply labels, while the sentences, built up from the same words and phrases, transmit thoughts, i.e. they are units of communication. Such one-member sentences can express a simple thought but the majority of sentences have a two-member structure and express more complex relations between the subject and the predicate,

 E.g.: The water froze. Cold water is bad for the throat.

The subject and the predicate are the main parts of the sentence and they form the nucleus of the sentence. These parts are independent. Apart from the main parts, a sentence may comprise also other words and phrases grouped around and dependent upon the subject and the predicate. They are called the secondary parts of the sentence.

4. GRAMMATICAL WELL- FORMEDNESS

We can summarize the following features of the sentence which distinguish it from other units of linguistic description: predicativity, modality, intonation and grammatical well- formedness. Among these predicativity ranks highest as a major distinguishing feature of the sentence. It reflects the close relationship between language and thought.