The function of the oblique moods is to represent something in the speaker's mind not as a real fact, but as a wish, purpose, supposition, doubt or condition, which is problematic or contrary to the fact. When the speaker expresses his wish by using one of the oblique moods, he merely communicates to the listener what he considers desirable [1; 2; 3; 9; 11; 20].
This is the main difference between the oblique moods and the imperative. When using the imperative mood the speaker directly urges the person addressed to fulfill his order or request [1; 2; 5; 9; 20]. Cf.:
- Be quiet! (I want to produce an immediate effect, to bring about some actual changes in the existing state of things: I want a noisy person to become quiet as the result of my urging)
- I wish you were quiet. (I merely inform the listener of what I consider desirable, indicating at the same time that my wish contradicts the actual state of things /= you are not quiet/)
- It is necessary that he (should) go there. (I make a statement of what I consider to be indispensable, leaving the question of its realization open)
There are four oblique moods in Modern English, two of which are synthetic and two are analytical. The synthetic moods are: Subjunctive I and Subjunctive II. The analytical moods are: the Suppositional mood and the Conditional mood [1; 2; 3].
NOTE: the two synthetic moods (subjunctive I and subjunctive II) are often united under the general name of the subjunctive mood [2; 3; 5; 9]; the two analytical moods (conditional and suppositional) are regarded as equivalents of the subjunctive. In some grammars the suppositional mood is not regarded as subjunctive, but as a construction with modal verb [17; 19].
