The mood of a verb is an area of verbal expression relating to the attitude with which a idea is expressed. A modal verb is an auxiliary verb that characteristically appears with a dependent infinitive and expresses a distinction of mood. A modal verb is a group of verbs (can, could, must, will, would, shall, should, may, might) used with an infinitive to express such things as possibility or necessity. Verbs have a quality that shows the attitude or purpose of the speaker. This quality is called the mood.
I can go.
A verb may take one of the following moods.