If music be the food of love, play on. Simple idea, but not so simple grammar: why if music be...rather than is?

The short answer is that be here is an old-fashioned use of the subjunctive mood, where we today would use the indicative is. A longer answer is that this simple idea has landed us in two tricky quagmires of English grammar, the subjunctive and the conditional sentence. A reader’s email dropped me in them last week, asking whether he should write if I was or if I were. Here are some guidelines to firm ground.

The conditional looks simple. If I were a rich man... (the condition), I’d... (the result). But it has traps. You may meet a sentence like If Mountbatten esteemed Nehru, he esteemed himself more. This isn’t a conditional at all: the last viceroy’s self-admiration did not depend on his view of Nehru. In fact, it’s a pretentious imitation of French. Shun it.

Beware of such shortened conditionals as should I discover that..., were I smarter... or had I known.... All these substitutes for if are idiomatic, but all — had rather less so than the others — smell a bit of the past, especially in speech. And not even poets should today imitate 17th-century Andrew Marvell’s plea to his mistress Had we but world enough, and time, this coyness, Lady, were no crime, where had simply means if we possessed. Yeats did it in Had I the heavens’ embroidered cloths, but we lesser mortals should steer clear.

Tongues of men

As for the subjunctive, few of us use it and often not even grammarians can tell whether it’s being used or not. That’s because — in every verb except to be, where it substitutes be for the indicative am, is and are — the two moods are identical, except in the third person singular: in place of I go, he goes, we/you/they go, the subjunctive uses I/he/we/you/they go all the way through. A famous passage in the 1611 translation of the Bible has St Paul writing Though I speak with the tongues of men and of angels.... Is that speak indicative or (more likely, in high-flown English in 1611) subjunctive? No one can be sure.

Still, where the two can be told apart, should you use the subjunctive? Not in conditional sentences. If music be the food of love is fine for Shakespeare, but if the bus leave on time (instead of leaves) would sound as affected in today’s Calcutta as it is improbable.

Yet every rule has its exception, the one raised by that reader’s email. In phrases like if he were wise or if I were you, that were is a bit of the subjunctive. It’s bizarre: it refers to the present, not, as one might expect, the past, and it always implies that the condition is unmet (actually, he’s a fool). But it is definitely preferable to if he was wise or if I was you. Both forms are acceptable (and with any other verb than to be you don’t even have a choice); but were is better than was.

There’s more to be said about the subjunctive — 156 pages more in the standard work on the subject. I’ll be back with it, though not at that length, next time round.