by Enigma » Mon Feb 22, 2010 5:44 pm
This is the best explanation I have read on the distinction:
Note, however, that they are traditional rules. Nowadays, according to many, the distinction is one of formality, not one of moods.
According to traditional rules, you use the subjunctive to describe an occurrence that you have presupposed to be contrary to fact: if I were ten years younger, if America were still a British Colony. The verb in the main clause of these sentences must then contain the verb would or (less frequently) should: If I were ten years younger, I would consider entering the marathon. If America were still a British colony, we would all be drinking tea in the afternoon. When the situation described by the if clause is not presupposed to be false, however, that clause must contain an indicative verb. The form of verb in the main clause will depend on your intended meaning: If Hamlet was really written by Marlowe, as many have argued, then we have underestimated Marlowe’s genius. If Kevin was out all day, then it makes sense that he couldn’t answer the phone.
Remember, just because the modal verb would appears in the main clause, this doesn’t mean that the verb in the if clause must be in the subjunctive if the content of that clause is not presupposed to be false: If I was (not were) to accept their offer—which I’m still considering—I would have to start the new job on May 2. He would always call her from the office if he was (not were) going to be late for dinner.
What you see, yet can not see over, is as good as infinite. ~Thomas Carlyle