Constituents and categories are theoretical constructs in linguistics. We do not think of our native language in terms of these categories and constructs. In fact, thinking about them often leads to confusion and uncertainty. This is because we generally intuitively know the correct structure of our language from a very young age. We of course, study some of the rules at school, but that is principally to fill in possible gaps in our knowledge and to enable us to understand the work of writers.
Linguists have come up with such theoretical ideas as categories and constructs in order to help us further understand the workings of language. It is a fact that we do not analyse a sentence, in speech, in the manner we have above. These categories and constructs were created after the language. They are useful in order to analyse the structure of the language, so it can be compared to other languages. It is also useful to ascertain the "rules" of a language.
Before we can justify the claim that "the true status of constituents and categories is that of theoretical constructs which must therefore be justified on empirical grounds", we must analyse and define the various important terms in turn. A constituent is defined by "A Dictionary of Linguistics and Phonetics", as being "a basic term in grammatical analysis for a linguistic unit which is a functional component of a larger construction. " As you can see a sentence can be broken down into constituents.
These would be a verb phrase or a noun phrase, just to name a couple of examples. Constituents can be further broken down into simpler constituents. As such a noun phrase can be divided into the constituents a noun and a determiner. The breaking down of a sentence into its constituents is known as constituent analysis. Constituent analysis can be continued until there are no further constituents. The constituent structure of a sentence is most commonly shown as a diagram (see Fig. 1), however, square brackets may also be used.
The term category has many different uses and meanings in linguistics. A category in categorical constituent structure refers to "the establishment of a set of classificatory units or properties used in the description of a language, which have the same basic distribution, and which occur as a structural unit throughout the language. In this case we are referring to the classes of language themselves, such as noun, verb, subject and determinant and their respective properties. Through out grammar there are more specific uses of the term category.
In categorical grammar, the two principal categories are sentence and noun. From these two categories all the others are determined. In scale and category grammar, category refers to class, system, unit and structure, which are the basics of the theory. The categorical component of generative grammar is the part that which determines the synaptic categories as being S NP and VP (sentence, noun phrase and verb phrase, respectively). In this easy a category refers to the first and last of the above definitions.
The original statement that "the true status of constituents and categories is that of theoretical constructs which, must therefore be justified on empirical grounds" emphasises that the justification of these theoretical constructs must be made on empirical grounds. To justify something empirically means that it must be justified based on observation or experience. To begin our justification of the statement, we must thus prove each of its assertions. We well start by discussing categories.
There are several sources of evidence to support the assertion that words belong to categories. Some words that are spelt identically are commonly referred to as being in different categories. One way are determining which category the word belongs to is to look at the phonology, or pronunciation, of the word. By placing stress on different syllables of a word we can determine what category it falls under. To give two examples: (1) We need to inCREASE productivity. (2) We need an Increase in productivity. (1) We might transFER him to another club. (2) He has asked for a TRANSfer.