I was in line at the grocery store the other day and I happened to overhear the person behind me say to someone on the phone, if I can help you, I will. The resolve and companionship of the pledge moved me, and later I wondered how very different my reaction could have been with the simple change of two words: if I could help you, I would. If there’s ever a place to see the living life of grammar, it’s right here.
Both of these statements constitute what are called conditional sentences. In an earlier post (In a Contrary Mood), I explained how a contrary-to-fact condition is constructed, but English grammar recognizes two other kinds of conditional sentences, real and ideal, along with statements called mixed conditions. This particular region of grammar is, let’s admit it, thick with jungle at times, so a few words here on real conditions will go far enough for us to begin to be aware of all that is implied in the sentences we say and hear every day.
All conditional sentences have two parts: the condition and the result. They very often begin with the conditional clause itself, identifiable by the subordinating conjunction if, with the result then following in the main clause. And, as we know, when a subordinate clause precedes the main clause, a comma separates the two: If I can help you, I will. Curiously, though (and here appears one of those great beasts of the jungle), the only thing a conditional sentence is really talking about is the connection between the two ideas expressed in the two clauses, not the ideas themselves. To say if I can help you is not the same as saying I can help you; and to say I will help you on the condition that I can is not the same as saying I will help you. Grammar and logic spend a lot of time together.
The various kinds of conditional sentences have to do with the nature of this logical connection. Real conditions state that the connection between condition and result is inevitable and factual: to say if I can help you I will means that it is absolutely certain—not merely probable nor outright impossible—that I will help you if conditions are such that I am able. Because the connection here between my being able and my actually helping is factual, the verbs in both the conditional and result clauses of a real condition are in the indicative mood, that form of a verb that states or queries for fact.
The connection between condition and result in contrary-to-fact conditions, on the other hand, is impossible. Had I heard the person on the phone say if I could help you, I would, my heart would have gone out to the poor soul listening to that sentence because the two subjunctive verbs, could and would, were meant to signal impossibility: the condition on which I can help you does not, in fact, exist in reality. That slight change in the mood of the verb, from indicative to subjunctive, is enough to change the nature of the world we share if only conditionally: one a world of fact, the other of impossibility.
The subjunctive mood, as current grammar books are quick to point out, is now, as one of them puts it, moribund: dying and almost dead. That is true, because we have as a culture become less patient with the shades of meaning that the subjunctive can elsewhere convey. One function of it, though, remains vital, and that is in the contrary-to-fact condition, where the inevitability of its demise is not yet certain.
Conditional statements, then, depend on the mood of the verb in each clause. The indicative mood conveys an almost mechanical connection: if this, then that. The subjunctive mood conveys a hypothetical connection, something true in theory only. And between these two is the ideal condition–a discussion best left for another time.