Mood is a verb attribute that is not hugely important in English for native speakers, though it can be very helpful to foreign learners, and the concept is of great value to English natives who are learning other languages. While the verb in English does not always inflect to show mood, the structures of the verb phrase and clause are used in such a way as to control the mood of sentences: most sentences are indicative (they are not marked in any way). If they are not, their word order controls whether they are interrogative or imperative.
The English verb has three or four moods (grammatically speaking):
- The imperative is the mood in which we give orders. Characteristically, the imperative has no stated Subject - "Do this!" we say, and we do not have to spell out who it is that we are talking to.
- The interrogative is the mood with which we ask questions. This is most often shown by alterations in word order. "Is the sun shining?" [aux + Subj + verb] is a question equivalent to the statement "Yes, the sun is shining" [Subject + aux + verb]; "Did John do it?": "John did it."
- "John did it" and "the sun is shining" are examples of the third, and by far the most common mood - the indicative. This is the form of the verb - the mood, indeed - which we use to indicate the facts about whatever is happening. "The sun is shining," we say (continuous aspect, present tense, active voice, indicative mood), or "Hull City won yesterday" (simple past tense, active voice, indicative mood) or "he was knocked over by the car" (simple past tense, passive voice, indicative mood) or "the child was being taken to school" (continuous past passive indicative). (See also indicative.)
- English-speaking students can be plagued by the subjunctive in learning European languages, where it tends either to indicate an element of uncertainty, doubt or futurity, for example in an 'if' clause; or to express certain kinds of dependency of a subordinate verb. The subjunctive hardly exists in English. Some forms of the verb which are known in EFL ('English as a Foreign Language') teaching as 'conditionals' are in a more rigorous classification known as subjunctives. There are also the forms used, in formal English at least, to describe an hypothesis which is actually impossible - the famous example is "If I were you." These forms look like a past tense, but they are used - at least in formal English - with different rules. In the indicative and interrogative moods, the form of the verb 'to be' usually used with 'I' - the first person singular of the past tense of 'to be' - is was. (There is no past imperative. Ordering someone to do something in the past is rather pointless.)
In some languages, there are other moods; but the above are the only ones current in modern English.