Ask if the verb makes a statement or asks a question. This determines if it is in the indicative mood, the most frequently used type of verb.
For example: In the sentence "Betty sets her alarm clock for 6:30 a.m.," the verb "sets" tells or indicates what Betty does.
Check whether the verb expresses a command or makes a request. This determines if it is in the imperative mood.
For example, in the sentence "Set your alarm clock for 6:30 a.m.," the verb "set" is telling you what to do, thus an imperative.
Check whether the indicative mood is replacing the subjunctive mood, which commonly occurs in informal English. The subjunctive typically is used in formal commands and requests, so often is replaced in informal speech and writing.
For example, instead of the imperative sentence "Submit a report, the teachers told him," the subjunctive form would be "The teachers demand that he submit a report."
The subjunctive mood also is used to state a condition or a wish that is contrary to fact. This use of the subjunctive always requires the past tense. For example: "If she were to oversleep she would miss her ride to school." The subjunctive mood uses "were," not "was."