The subjunctive is what in grammar is call a mood rather than a tense. It is used to describe hypothetical wishes or suggestions. In the famous song from Fiddler on the Roof, Topol sings
If I were a rich man, I'd build a big, tall house...
This expresses a dream or remote ambition rather than a likely outcome.
Grammatical features
There are three grammatical moods in English. The other two are indicative mood (to expresses facts) and the imperative mood (to expresses commands).In modern English, the subjunctive is most easily identified through specific examples rather than in fixed verb endings.
When is the Subjunctive Used?
To express wishes and/or hypothetical situations:
- "If I were you, I'd take the bus."
- "I wish I were able to..."
- "If it were up to me, I would..."
After verbs expressing abstract wishes:
- "I suggest that he take the A train."
- "They demanded that we publish the full text ."
In clauses introduced by "That":
- "Our president insisted that an explanation be given."
- "We tried to ensure that you not be disturbed."
In clauses introduced by "As If/As Though":
- "It's not as if he knew the answer."
- "They behaved as though they were on holiday."
In specific idioms/expressions:
- "God bless you."
- "Should you need further information..."