The grammatical constituents in a sentence like Noun Phrase, Verb Phrase, Adverbial and Preposition Phrase can be further divided into categories such as Noun, Adjective, Verb, Tense and Morpheme.
Now, the question arises as to how we should make the cuts. The answer lies in the notion of ‘expansion’.
A sequence of morphemes that patterns like another sequence are said to be an expansion of it. One sequence can, in such cases be replaced by another as similar sequence patterns will appear in the same kind of environment. Here is an example of similar sequences in the expansion that can fit into the same slot:
(1) Daffodils
(2) Yellow daffodils
(3) The yellow daffodils.
(4) The yellow daffodils with a lovely look.
The elements 2, 3 and 4 are expansions in the above set, i.e, ‘daffodils’ is the headword, whereas the other words in 2, 3 and 4 are modifiers. Incidentally, the set of examples given above can be grouped under the term noun phrase (NP).
There are no hard and fast rules for determining the ICs of a construction. The native speaker’s intuition tells him where the most fundamental cut should be. He will cut it into pairs in which he feels the closest and the most direct relationship exists. Henry Allan Gleason suggests the following methods to determine the ICs of a construction.
(1) The basic method is that of comparing samples. For, example, let us divide the construction ‘her son’s school’ into its ICs. This may be divided into four ways:
(a) her/son’s school
(b) her son’s/school
(c) (her) son’s (school) -‘son’s’ is one IC and ‘her…school’ another
(d) her / son’s / school
If the construction had only two constituents, there would be no problem. E.g., old/man. Let us find a two-word construction, which is directly comparable with her son’s school, some construction that can occur in similar environments and is alike in the features used to mark syntactic relationships. Sam’s school is such a construction. Since Sam’s can replace her son’s the two may be regarded as equivalent and we will divide the construction as her son’s/school; Sam’s/school. Such a comparison helps us to identify ICs in many cases, but not in all. Great care has to be taken to make sure that the constructions compared are comparable.
(2) Suprasegmentals play a decisive role in assisting the native speaker to determine the IC cuts. These features are the decisive evidence for syntactic structure. Only constructions with similar stress and intonation should be compared, since occasionally pairs of utterances of identical constructional types may be pronounced with different stress and intonation.
(3) One useful test for determining ICs is that of freedom of occurrence. If we break up an utterance into smaller parts, we find that these parts occur in other utterances also. The shorter portions like words and inflectional endings occur more freely than the longer ones. A sequence that is a constituent has greater freedom of occurrence than one which is not. Thus, if we cut Old/Light Church as we would old/lighthouse, we will find that Light Church occurs in very few contexts such as New Light Church, whereas lighthouse occurs in a great variety such as a new lighthouse, pretty lighthouse, etc. The native speaker learns the correct cut by his familiarity with the constituents in several contexts.
(4) Yet another useful test for ICs is substitutability. When we compare ‘her son’s school‘ with ‘Sam’s school‘, we were assuming that they have the same constructional pattern and constituents. ‘Same’ here does not mean identical or even similar in form or meaning, but only that they are alike in their potentiality for entering into constructions; they should enter into several constructions otherwise is identical, i.e., one should be substitutable for the other.