IN A recent supplement to The Economist, called “The World If”, we considered several hypothetical futures under such headlines as: “If Donald Trump was president” or “If the ocean was transparent”. Several readers wrote in dismay: surely we meant: “If Donald Trump were president” and “If the ocean were transparent”. Does no one know the English subjunctive anymore?

In fact, the decision to use “If the ocean was…” was made consciously, after some debate. It looks less stilted in a headline. It feels a bit less distant from reality. And because of the design of the pages, the words “…the ocean was transparent” stood alone. They would have looked bizarre as “...the ocean were transparent”.

Normally we would not let design considerations govern grammatical ones. But is there a case to be made for “if he was...”? Yes. There is a reason grammar books must hound people to use “if he were…” Most English-speakers use “if he was” at least some of the time in sentences that call for the subjunctive, and some of them use it exclusively.

How could this arise? Subjunctive “were” is an odd bird. Since Joseph Priestley in 1761, grammarians have fretted that it was on its way to disappearing from English. There are 37,704 verbs in the Oxford English Dictionary; only one has a special subjunctive form—“to be”. Even then, “to be” has a special subjunctive for only two of the six grammatical persons: first-person singular and third-person singular. In the other 37,703 verbs the subjunctive (“if we had”) looks just like the ordinary indicative (“we had”).

As it always does, incidentally, for all those other verbs. “If you ate that, you’d get sick” is the subjunctive; the “if” clause is about an unreal, hypothetical situation. But “if you ate that, I’m mightily impressed” is indicative (the “if” clause indicates something that is quite possibly true). Both forms of “ate” look like the plain past tense, though. It’s an odd theory of grammar to say that English has a full, robust and mandatory subjunctive, and yet that in almost every instance, it looks just like the plain past tense.

Major bits of grammar—like the existence of a subjunctive—are usually a lot more visible than this. The subjunctive has a distinct form for all verbs in many languages. In Spanish, for example, sabe (he knows) becomes sepa. It’s required to describe doubts, as in “I don’t think he knows…” Portuguese even has a future subjunctive (for “when he comes tomorrow…”), and German has one for reported speech (“She said that she is…”)

The English “were” is the runt of the subjunctive litter, used on just one verb, just some of the time, and not by everyone. And some experts reckon this is not a subjunctive at all. “The Cambridge Grammar of the English Language”, by Geoffrey Pullum and Rodney Huddleston, calls counterfactual “were” the “irrealis”, rather than the subjunctive, and says that it is an unstable remnant of an earlier system.

They reserve “subjunctive” to describe a fuller and healthier bit of English: things like “so be it”, “come what may”, and “he insists that students be punctual”. Other grammarians call this the English present subjunctive, and say that “if he were” is the past subjunctive. Messrs Pullum and Huddleston reply that the present subjunctive is so different from the “if he were” cases that the term “subjunctive” makes little sense covering both—hence their proposal of irrealis for the “if he were” cases. Outsiders to academic linguistics are often shocked that there is debate on basic facts like what the subjunctive is. But language is much more complex than short-and-sharp grammars portray. (The “Cambridge Grammar” is not one of those, at 1,842 pages.)

The fact is that “if he were” is still in good health in edited English: it is not archaic like the King James Bible’s “If he be poor” (yet another subjunctive). But “if he were” is slightly formal, a bit tricky and not universally observed. Our choice of “If Donald Trump was…” comports with the many grammar books that consider “if he was” simply less formal. Defoe, Swift and Addison were using “was” in such sentences three centuries ago.

Many people think that grammar always gives a single answer to any question. But it doesn’t. In the recent Coen brothers film “Hail, Caesar!”, a stuffy older English film director struggles endlessly to get a backwoods-bred young American actor to master a single line, which both includes and sums up the subjunctive: “Would that it were so simple…”