Mood (definition)

identifies what the speaker is doing with the preposition in a situation. Most of the time mood is inflectional on the verb and is referred to as mode or modality. There are modal auxiliaries as well (Ex. Ought, may, could). Mood also classifies phrases into different categories. They are indicative (the usual form), imperative (command), and subjunctive (subordination).

Reference

Crystal, David. A Dictionary of Linguistics and Phonetics. The language library. Oxford, UK: Blackwell, 1997.