A student of mine told me that he had found a mistake in the lyrics of the national anthem of the United Kingdom. He said the name of this anthem, God Save the Queen, had a missing -s after the verb save. The subject, God, is singular in the third person, therefore the verb should be conjugated to agree with the subject accordingly.
Of course it’s extremely unlikely that such a silly mistake would be made in the name of a national anthem. This innocent bare verb save is actually in the subjunctive mood, which is identical in form to the infinitive form in English. Therefore it should not carry the -s which appears in the present tense in the indicative mood.
I cannot emphasize enough that mood is a different concept from tense. Tense tells us about the period of time in which an action takes place, be it in the past, the present or the future. Mood tells us about the function of the sentence, be it a declaration, a question, a command, a request, a wish or an encouragement, but to name a few possibilties. (See What’s in a verb?)
In particular, the subjunctive mood is used to tell the listener that the action or event described is something that can possibly happen, but not something that has actually happened. In practice, this oftens means a wish, a request, a suggestion or a condition.
The national anthem, God Save the Queen, is therefore meant to be a blessing, a wish, not a statement which declares the truth. In fact, many familiar blessing phrases in English are in the subjunctive mood. Consider “God bless you”, “Long live the King” and “God be with you” (which was shortened to become the word Goodbye), and other expressions like “until death do us part” and “so be it”. We may find that such phrases are mostly fixed idiomatic expressions. Indeed, the subjunctive mood is used less often now than in the past. It is now very commonly replaced by the indicative mood, often in the present or the future tenses. Consider the following sentences:
1. It is important that we be humble. (subjunctive)
2. It is important that we are humble. (indicative)
However, the subjunctive is still very productive in irrealis situations which propose imaginary conditions, especially in the so-called Type II and Type III Conditional sentences.
3. If I won the lottery, I would go traveling around the world. (Type II Conditional)
4. If I had won the lottery, I would have gone traveling around the world. (Type III Conditional)
Traditional grammar books often describe the verb win in (3) and (4) as in the simple past and the past perfect tenses respectively. In fact, they fail to mention that they are in the simple past and the past perfect tenses in the subjunctive mood. This explains why the verb be becomes were in a Type II Conditional sentence, as in (5), for the past subjunctive form of be is were.
5. If I were you, I wouldn’t do that. (Type II Conditional)