subjunctive mood

First, understand this: The word mood has nothing to do with frame of mind, as in happy or sad. It actually refers to mode, which is the attribute of a verb suggesting the speaker's attitude toward the action expressed.

The mood of verbs shows how the speaker regards the utterance. The speaker might regard the utterance as a statement: that's the indicative mood. The speaker might ask a question: that's the interrogative mood. The speaker might issue a command: that's the imperative mood. Or the speaker might state a possibility, hope, wish, or hypothetical: that's the subjunctive mood.

The subjunctive mood is used when you need to (1) depict situations contrary to fact, (2) express a wish, (3) express a supposition, (4) issue a command, (5) make a suggestion, or (6) show necessity.

You form the subjunctive of action verbs by using the plural form of the verb, even in situations calling for the third-person singular, as in The law requires that an applicant file the document within 30 days.

You form the subjunctive of the verb to be by using the plural were, even in situations calling for the third-person singular, as in If I were you, I'd file the papers at once.

Many writers incorrectly think that the word if must always be followed by were when the verb to be appears. Not so. The test is whether the writer is trying to say something hypothetical or contrary to fact.

Please read the chapter on the subjunctive mood in the section on Common Grammatical Mistakes on Grammar.com. Click here for the beginning of that discussion. You may also download the eBook Common Grammatical Mistakes.