Mood is an indication of the purpose or intent of the sentence (its manner of use).

English verbs have three moods- the declarative, the subjunctive and the imperative.

Declarative Mood

The declarative is used to make statements and to ask questions.

XXXMs. Wilson ia a doctor.         Do you know the way to San Jose?

Subjunctive Mood

The subjunctive mood is used to express a wish or a condition which is contrary to fact. It is often found in
if- then statements.

XXXIf I were a rich man, I would buy a mansion on a beach.

Imperative Mood

The imperative mood is used for commands, requests, or instructions. The subject is always the pronoun
‘you’, but the word ‘you’ is usually implied and is seldom in the sentence.

XXX(You) Look yout!                        Stop that!

Other links for Mood
XX Verb Mood
XX Function of Mood
XX Mood for Grammar

An explanation of mood in English and the three moods: subjunctive, imperative and indicative mood–