The Mood system

THE MOOD SYSTEM

The auxiliary which functions in initial position is called the OPERATOR. It performs four main functions in the verbal group, which we shall shortly go on to describe. These will be discussed more fully individually, but can briefly be listed as follows:-

(1)	*MOOD, which selects between imperative, declarative* and interrogative moods;**
(2)	*FINITENESS, which refers to whether the verbal group is finite* or non-finite;**
(3)	*POLARITY, which selects between positive* and negative;**
(4)	*EMPHASIS, which determines whether the verbal group is emphasised* or not.**

We shall describe the features of medial and final elements more specifically later. For the present, however, we can note that verbal group structure is subject to the following conditions:-

(a)	the initial position or operator can be any of the auxiliary verbs;
(b)	the modal auxiliary verbs can only function in the verbal group in initial position - i.e. as operators - they do not occur in medial or final positions;
(c)	the final position is always occupied by the main verb.
(d)	only the initial element in the verbal group is finite; medial and final elements are non-finite.

We shall now go on to consider in more detail the initial systems which govern the functioning of the operator element in the verbal group.

THE MOOD SYSTEM

As we saw earlier, the system of mood governs the basic structural features of the sentence - whether the sentence chooses between declarative, interrogative or imperative forms. The mood system is thus the part of grammar which is most inherently linked with the roles which speakers adopt in the use of language.

We can think of the way we use language interactively as a form of exchange, and we can understand the function of language in exchange in two ways:

(1)	*where language serves as a means of exchanging goods and services, and influencing the behaviour of others;*
(2)	*where language is itself the medium of exchange* in the form of information.**

As participants in these interactive exchanges we have to assume whichever of the various roles which serve these functions may be appropriate. Thus we may be required to express requests for services or information, or to provide information or service for someone else, to give instructions, warnings, make demands, pay compliments and so on. In such activities we adopt, assign to others or have assigned to us the appropriate participant role in the exchange.

Mood is thus the primary system which is associated linguistically with this speaker role in interaction. This function is performed by the structural relationship between the subject and the predicator. Consider the following examples of indicative mood contrasts between the declarative and interrogative forms, in which the verbal groups have been underlined.

e.g.	(1)	The cat is on the mat.
		Is the cat on the mat?
	(2)	He wrote a play.
		Did he write a play?
	(3)	She has a headache.
		Does she have a headache?
	(4)	The cat has eaten the fish.
		Has the cat eaten the fish?
	(5)	I could write a sonnet.
		Could I write a sonnet?

We can see from these examples that mood is determined not by the position of the entire verbal group, but only the first element in it. As we saw above, this element is the operator, and is in fact an auxiliary verb. It is the structural relationship between the operator and the subject which indicates whether declarative or interrogative forms are selected, since the position of the main verb remains unchanged in both forms.

In (1), the verbal group consists only of a single word, "is", and this is formed from the verb BE which has a number of special features. It may function both as a main verb and as an operator, and is almost unique in that when it is a main verb, as in this example, it forms its interrogative without the use of an additional operator. (The only other verb which occasionally may do this is the verb "have" - e.g. Have you any money?).

Example (2) consists of a verbal group "wrote" in the declarative, comprising only one element which is the main verb. The interrogative is formed by adding the operator "did", and this is the special function of the verb DO - it is the operator which signals the interrogative. For main verbs then, the minimal group in the interrogative consists of at least two elements - the operator formed from "do" + the main verb.

Example (3) is similar to (2) in that the declarative consists of a single verb element "has", which is here a main verb. The interrogative is formed as in (2) by means of the operator "does".

Example (4) features a two element group in which "has" is an auxiliary verb, and here functions as the operator in signalling mood. The interrogative is thus formed by inverting the operator - subject sequence in as split predicator.

In example (5), the verbal group includes a modal auxiliary, which here again also functions as operator in the mood system. The interrogative is likewise formed as in (4) by inversion of the operator - subject sequence.

We can summarise these observations as follows:-

(1)	a verbal group which consists of a single position in the declarative mood - which is thus the main verb only - forms its interrogative by incorporating the auxiliary verb DO as operator in initial position, and preceding the subject;
(2)	a verbal group which consists of more than one position in declarative mood - which thus already has an auxiliary in initial position - forms its interrogative simply by a split predicator inversion of that same auxiliary and subject;
(3)	the operator DO cannot be used to form the interrogative for the verb BE - this is realised by simple inversion of the subject - verb sequence.

We have seen that the basic structure for the verbal group is auxiliary + main verb, which we may abbreviate as follows:-

aux + v

The sequential structure for the indicative mood is thus as follows, where S = subject and brackets indicate optional inclusion:-

The sequential structure for interrogative mood is then:-

The actual form of the interrogative is dependent upon the form of the equivalent declarative structure, for where there would be no auxiliary present in the latter, then the auxiliary DO must be employed in the formation of the interrogative.