This is the second installment in my series about how English verbs are described in The Cambridge Grammar of the English Language. I’ll assume you’ve already read the first installment, in which I overviewed the forms of lexical verbs. Soon I will explain how the auxiliary verbs fit into the picture, but first I need to lay some groundwork by describing how the English language uses the past tense.
There may be errors herein, but I will correct any that I become aware of as soon as possible.
When we talk about the past tense, we usually mean the verb form exemplified by words such as “looked“, “cooked“, “walked“, “talked“, “thought“, “taught“, “wrote“, “rode“, “flew” and “drew“. In The Cambridge Grammar this form is called the preterite, and it is used in a variety of ways.
Obviously it is most frequently used to refer to things that happened in the past, e.g. “I wrote the letter“, but that is not the whole story. Consider a sentence such as: “The linguists’ strike started tomorrow, but they’ve decided to cancel.” This is an example of what The Cambridge Grammar calls the past futurate, and in this example, the word “started” can be thought of as a shorthand for “was scheduled to start“.
Two of the most interesting uses of the past tense are called modal remoteness and backshift.
Modal remoteness is where we emphasise that an eventuality is hypothetical. The word modal refers to mood, which is a term linguists use to distinguish whether a sentence describes something as certain, probable, hypothetical, desirable, etc. Compare the following two sentences:
- If I write a letter tomorrow, I will be out of paper until Monday.
- If I wrote a letter tomorrow, I would be out of paper until Monday.
The first version (with present tense “write“) probably sounds as though I’m seriously considering that I’ll write the letter tomorrow, whereas the second version (with past tense “wrote“) probably sounds as though I’m less likely to do so. In other words, it is more hypothetical, a more remote possibility. Note also that we replace the auxiliary verb will with would. This observation leads to a conclusion which may surprise you, which is that would is actually the preterite of will. Similarly, could is the preterite of can, as we can see by comparing:
- If you want me to write a letter, I can do that.
- If you wanted me to write a letter, I could do that.
We will re-visit the preterites of auxiliary verbs when we discuss the auxiliary verbs in detail.
Modal remoteness is also why the preterite is used in “I wish I knew what to write about“. In this case, it is obligated by the verb “wish“, which by definition refers to something hypothetical. In general, though, the question of when these things are permissible or obligatory is beyond the scope of this series; I am simply trying to explain what they are.
Sometimes if an outer clause uses the past tense or refers to events in the past, we use the past tense in an inner clause as well, even though the inner clause doesn’t actually refer to the past at all. This is called backshift. Consider these examples:
- You assured me the old letters were in the cupboard.
- I wish I knew where the old letters were kept.
- I remember you saying that the old letters were in the cupboard.
All three examples could refer specifically to the past depending on the context (and are ambiguous in that respect) but we are concerned with the interpretation in which they refer equally to the present. In the first example, the outer clause uses the preterite “assured“, so the inner clause “the old letters are in the cupboard” is backshifted to match it (hence “weren’t” instead of “aren’t“). In the second example, the inner clause is backshifted to match another preterite (in this case, “knew“), but in this case the outer preterite expresses modal remoteness, not past time. In the third example, inner clause is backshifted because the outer clause refers to an event in the past, even though it does not actually use a past tense.
Backshift is often used as a literary device for describing a character’s thoughts, as in “She wondered whether she would ever find the letter“. In this sort of example, the context adjusted for can be an entirely seperate sentence rather than an outer clause. For example, “She wondered what would happen now. Would she ever find the letter?“.
We must now turn to a matter that I briefly mentioned in the first installment, wherein I said that “there are good reasons to think of the so-called perfect as a different type of past tense“.
In English, the perfect is indicated with the auxiliary verb “have” (in conjunction with a past participle), as in “I have written a letter“. One way to explain the difference between that and the simple preterite is that “I wrote a letter” is a statement about the past, whereas “I have written a letter” is really a statement about the present, even though what it says about the present is that it comes after the time when I wrote the letter. This is easier to see in a sentence like, “I will have written a letter by tomorrow“, which is clearly a statement about tomorrow, not about the time when I will write the letter.
To put it another way, the preterite usually describes an event that is in the past now, whereas the perfect describes an event that is in the past relative to some other indicated time, and when we use it we are really talking about that indicated time rather than the time of the event described. English grammar is (as always) more complicated than this simple summary, but it will do for now.
Linguists often regard the perfect as an aspect rather than a tense. Aspect is a third type of distinction that languages can make, in addition to tense and mood. It involves such things as whether a sentence describes a specific event, an ongoing situation, or something that happens repeatedly. If we were talking about languages in general, there might be good reasons to say that the perfect is an aspect, but The Cambridge Grammar is about English specifically, and so it categorises things in the way that makes most sense for English.
In English, the preterite and the perfect have a great deal in common. One remarkable similarity is that the perfect, just like the preterite, can express modal remoteness and backshift. This is most often done when the event is already in the past. For example, the following two sentences both describe events in the past, but the second uses the perfect to express modal remoteness.
- If you asked me to write a letter, I didn’t hear you.
- If you had asked me to write a letter, I would have done so.
As for backshift, we noted earlier that sentences like “I wish I knew where the old letters were kept ” and so on are ambiguous: the preterite “were” can indicate either backshift or past time. If we want to indicate both simultaneously, we could write, “I wish I knew where the old letters had been kept“. This makes it clear that we’re talking about where the letters were kept in the past, but it involves backshift too. This is achieved by using the perfect in addition to the preterite.
Because they have so much in common, The Cambridge Grammar describes the preterite as a primary past tense and the perfect as a secondary past tense.
In the third installment, I will start discussing the auxiliary verbs in detail.