Mood forms are individual morphological realization of the moods in each language, the number of which will depend on how many variables like person, number, voice, etc are involved. On the semantic level there are mood contents, the meanings conveyed by the mood forms by themselves or in conjunction with specific syntactic devices. But mood forms and mood contents need not always have a one-to-one correspondence. In English, for example, one can utter a command / request in the form of a question:
(1) a. Step out of the swimming pool (please)
b. Will you (please) step out of the swimming pool?
c. May I request you to step out of the grass?
All the above three sentences have similar mood content, which keep them apart from sentences such as the sentences given below.
(2) Somebody’s treading on the grass.
(3) Is there someone treading on the grass?
The sentences (1), (2) and (3) differ from each other in the sense that they are different types of messages. In (1) someone is asked to do or not to do something. Sentence (2) is used to convey a piece of information and (3) to elicit information. But the differences among 1.a, 1.b and 1. c are of another kind: style, degree of politeness, emotive elements, etc., are some of the factors involved.