In a recent post (What Happened When), we looked at the difference between the simple past and present perfect tenses. We saw that the simple past points to the occurrence of an action, and the present perfect to an occurrence and its consequences. So we say that the sun rose versus the sun has risen, the first bringing our attention simply to the event in itself, the second suggesting that what happened has produced new and present results: the sun has risen, so it’s time to get going.
But how are we to understand the arrangement of time in a sentence like this: If we wait until 7:30, the sun will have risen already. To fill out the context, let’s imagine we’re on vacation and the plan is to get up early to see the sun rise the next morning over the ocean. The statement has two clauses, and they have been arranged together in what is called a conditional sentence. In their simplest configuration, conditional sentences have two parts, a conditional clause (called the antecedent) signaled by the conjunction if, and a result clause (called the consequence) sometimes signaled by the adverb then, and sometimes not. It is common to find the conditional clause first, as in our example, but the reverse is also possible: The sun will have risen already if we wait until 7:30. Read any kind of conditional sentence closely and you’ll discover something interesting. Conditional sentences do not assert what is; rather, they assert how what is might be connected. Theirs is not a world of fact, but of hypothesis.
Be that as it may (and let’s let it be because the subject of conditional sentences will swoop us up terrifically into the territory of logic and away from our present concern with tense), the first clause of our example denotes its moment with a simple present tense (if we wait), and marks a point of time we should note carefully. The hour of 7:30 is being projected into the future from the present moment of saying the sentence. In reality, then, the first clause gives us two marks of time, the explicit hour of 7:30, and the tacit, or implied, hour of, let’s say, 5:30 (we’ve all gotten up early and are deciding when to leave to see the sun). The second clause of our sentence, then, denotes its time with the future perfect tense (will have risen already), and with that peculiar tense marks yet a third point of time, some unstated hour between the two already given and implied in the first clause.
I call the future perfect tense peculiar because it manages to overpower logic and unite contradictories. The term perfect in grammar means completed, or past, and so the very name of the tense causes trouble: a future perfect tense is really a future past tense, an impossible confusion that can only be sorted out by remembering that relativity has its rightful place in the order of things. The future perfect tense means to say that the action it is referring to is future relative to one moment and past relative to another. So in our example, to say that the sun will have risen already, is to say that that magnificent event will be future to the present moment of speaking (the 5:30 we conjectured) and past to the future time of 7:30, when the sun will already be above the horizon. The future perfect tense must always involve three points of time, but not all necessarily, as we have seen, explicitly stated.
The lesson once again has to do with how keenly we are perceiving the ideas we wish to convey, for in precision lies style. As writers, like all artists, we have something we want to say, to communicate, to share. It is true, of course, that we discover more fully what that is by working with our materials, but what we release to our audience should not be a working draft, but a whole complete within its scope, something to be understood in its own right as far as it has undertaken to go. Proper tenses are an integral part of rational statement, the canvas of expository prose, and we say more clearly what we have to say by choosing the proper tenses and coordinating them accurately.