Mood, also called mode, in grammar, a category that reflects the speaker's opinion about the ontological character of an event. This character can be, for example, real or unreal, certain or possible, desired or required.
Indicative Mood
This mood is used to express a fact statement. The verb in the indicative mood expresses an action as a statement of fact.
Imperative Mood
This mood is used to express a command or a request statement. The tone of the sentence is a direct command, not a mild suggestion.
Interrogative Mood
This mood is used to express a sense of uncertainty by asking a question. The question contains an auxiliary verb (helping verb) and then a main verb.
Subjunctive Mood
This mood is used to express a wish, doubt, demand, or a hypothetical situation. The verb in the subjunctive mood always changes.