A Grammatical Mood is a Relationship Type between a Verb and the intent of the Sentence. (a Verb Category??).
- 1. (grammar) A type of the relationship of a verb with reality and intent.
- (Wikipedia, 2009) ⇒ http://en.wikipedia.org/wiki/Grammatical_mood
- Grammatical mood is one of a set of distinctive verb forms that are used to signal modality.  It is distinct from grammatical tense or grammatical aspect, although these concepts are conflated to some degree in many languages, including English and most other modern Indo-European languages, insofar as the same word patterns are used to express more than one of these concepts at the same time.
- Currently identified moods include conditional, imperative, indicative, injunctive, optative, potential, subjunctive, and more. Infinitive is a category apart from all these finite forms, and so are gerunds and participles.
- The distinction of affirmative and negative is not mood but polarity. 
- In the grammar of many languages there is a concept of grammatical mood, which describes the relation of the verb to reality or intent in speaking. Many languages express distinctions of mood by changing (inflecting) the form of the verb.