2. Linguistic forms and syntactic functions

Language units represent mental concepts by means of their forms and function. In this module the following points are outlined: the system-and-function approach to the language study that is aimed at structural arrangement on a scale of language unit rank; in the focus of attention are the classes into which these units can be divided, the elements they are composed of, and realization by means of which the units of one rank are related to those of another.

2.1. Language units and their ranks in the system

A unit may be defined as any stretch of language which constitutes a semantic whole and has a recognized pattern that is repeated regularly in speech or writing. The previous sentence, for instance, is a unit containing other units such as syntactical groups a recognized pattern and in speech and writing. Sequences such as defined as any and repeated regularly in, that also occur in the same sentence, do not constitute units since they form neither a semantic whole or a syntactic pattern. The following stretch of language which comments on the effects of a nuclear accident constitutes one syntactic unit which is composed of further units: The effects of the accident are very serious. In English, it is useful to recognize four structural units which can be arranged in order of magnitude on what is called a rank-scale:

Unit	Boundary marker	Example
Clause	///	/// the effects of the accident are very serious ///
Group	//	/// the effects of the accident// are// very serious ///
Word	/ (a space)	/// the / effects / of/ the/ accident// are// very /serious///
Morpheme	{ } + { }	/// {the} / {effect} / {-s} / {of} / {the} / {accident} // {are} / {very} / {serious} ///

For the initial stages of analysis it may be helpful to mark off the boundaries of each unit by a symbol, such as those in the example. The symbol for 'clause boundary' is ///, that for 'group boundary' is //, that for 'word boundary' is simply a space ( / ), as is conventionally used in the written language. The independent clause is the equivalent of the traditional 'simple sentence'.

The hierarchal relationships between the units is as follows: each unit consists of one or more units of the rank below it. Thus, a clause is built up of groups, a group – of words and a word – of morphemes. For instance, Take care! consists of one clause, and it is built of one word group, two words, each consisting of one morpheme. More exactly, we should say that the constituent structure of each unit is composed with the units of the lower rank. The constituent structure of these units will be described in the next section together with their functions and meanings.

2.2. Classes of units

At each language layer there is a class of linguistic units which, when brought together, form a language sub-system with specific types of relations (microsystem).