Tense agreement in the past irrealis conditionals

Question

The following is taken from PEU¹ 123.5:

Could have + past participle can refer to present situations which were possible but have not been realised.

He could have been Prime Minister now if he hadn't decided to leave politics.

We could have spent today at the seaside, but we thought it was going to rain, so we decided not to.

The above two are the examples of past irrealis conditionals.

But I just don't understand why "now" / "today" agree with the past tense (could have been Prime Minister now / could have spent today).

I would think they should be like this:

He could be Prime Minister now if he hadn't decided to leave politics.

We could spend / be spending today at the seaside, but we thought it was going to rain, so we decided not to.

Do these two alternatives make sense? How do they differ from the original ones?

Edit:

Interestingly, as @Fantasier suggested, PEU 259.3 also introduced a similar usage:

We sometimes use structures with would have ... to talk about present and future situations which are no longer possible because of the way things have turned out.

It would have been nice to go to Australia this winter, but there's no way we can do it. (OR It would be nice ...)

If my mother hadn't knocked my father off his bicycle thirty years ago, I wouldn't have been here now. (OR ... I wouldn't be here now.)

But PEU failed to provide more explanations about why this is acceptable and how native speakers think of and use it.

^{1. PEU = Michael Swan's, Practical English Usage.}

Answer 1

As Geoffrey Leech (Leech 2004) puts it, “Past hypothetical meaning and the use of the modals is one of the most difficult areas of English not only for non-native speakers, but also for native speakers” (p. 127).

I have always thought that the oversimplified rules of conditional use, so common in old-style textbooks and no longer used in linguistics, should have been abandoned long ago. Your question is a case in point. Obviously, traditional rules cannot explain such sentences.

It is much better to think of (what is commonly referred to as) conditionals type 2 as unlikely (Huddleston’s remote) and conditionals type 3 as impossible (Huddleston’s doubly remote), without any reference to present, past, or future.

Trying to keep both analyses, Leech 2004 somewhat struggles and argues that “[t]here seems to be a growing tendency, in fact, to associate the Perfect after a secondary modal purely with ‘contrary to fact’ meaning, rather than past time” (p. 128).

He also observes that in such sentences, when modals are followed by perfect auxiliaries (in the main clause), “the past meaning of the Perfect seems to have been lost” and only the ‘contrary to fact’ meaning is applicable.

Mittwoch, Huddleston, and Collins 2002 - more linguistically oriented - offer a much better analysis (see Chapter 8 in The Cambridge Grammar of the English Language). They call such constructions doubly remote (conditional) constructions. They give the following examples:

[48] i. If you had told me you were busy I would have come tomorrow.

ii. If you had come tomorrow you would have seen the carnival.

iii. If your father had been alive today he would have been distraught to see his business disintegrating like this.

They argue that the perfect auxiliaries express modal rather than temporal meaning (p. 754). Huddleston 2002 (Chapter 3 in the same grammar) adds that the difference between remote and doubly remote constructions is "not very tangible," cf. his examples below

[6] i b. If they were alive now they would be horrified.

c. If they had been alive now they would have been horrified.

To conclude, Huddleston also argues that doubly remote constructions are "fairly rare" (p. 150).

Answer 2

As a native speaker, this 'single point in time' thing mentioned in the other answers doesn't make much sense to me.

Instead, to start with, the words 'today' and 'now' don't really have anything to do with it; 'now' doesn't add much to the first sentence: it is perfectly grammatical without it (though with a slight difference in meaning), and the same grammatical rules apply without it. 'Today' is only required in the second sentence because of mere coincidence: in this meaning, the verb 'spend' requires an adverb of time to complete it. But that's only because the verb 'spend' was chosen.

Here's a clearer example:

We could have hiked the trail, but we thought it was going to rain, so we decided not to go.

Here are the two alternatives based on your suggestions:

We could be hiking the trail, but we thought it was going to rain, so we decided not to go.*

We could hike the trail, but we thought it was going to rain, so we decided not to go.*

Neither of these sentences are natural English.

I think the best way to think of what is going on is that this kind of sentence describes a 'lost opportunity'. And in describing this kind of 'lost opportunity' English only allows past conditionals, even if that fact has consequences for today or for the future. You can think of it as "the opportunity is over and has moved into the past."

Compare the following:

You could have been rich if you hadn't wasted your youth.

The sentence is like saying 'you haven't been rich in the past, you aren't rich now, and you won't be in the future, because of what you've done in the past.'

Similarly:

If only I had bought that lottery ticket! I could have been rich!

= I had the opportunity to be rich...I don't have it any longer.

Here's an even simpler example. When you're stopped to turn at an intersection, and fail to do so even when you have the opportunity (because you're overanxious about oncoming traffic), you might afterwards say

I could have gone!

I could go/I could be going would be completely incorrect for this kind of "lost opportunity."

Answer 3

Without going into too much technical stuff, you are treating the word "today" as a single point in time, grammatically. Therefore the past tense works better than present tense in your 2 examples.

I think it's called the Third person desiderative mood. 1st person would say:

"I could have been prime minister..." "I could have gone to the beach today..."

But in reality, both are acceptable, you would just need to reword the rest of the sentence to bring the tense into alignment.

Answer 4

'Today' is treated as a single point in time grammatically, therefore it's already past, which is why past tense is being used. As Weevill said.

I support this answer because 'today' and 'now' are referred to one point in time. However, 'today' means On or in the course of this present day which does not change forms. Today is today and will be today if comes in a sentence.

Going back to your original question.

I just don't see why "now" / "today" is used in the past tense (could have been Prime Minister now / could have spent today).

When we use 'could have been', it means 'something didn't happen which supposed to and directly connected to the present situation. However you don't need 'now' in the first sentence. 'He could have been a Prime Minister, if he hadn't decided to leave politics.' This statement is good enough for a listener to understand what you mean.

We could have spent today at the seaside, but we thought it was going to rain, so we decided not to. This statement needs an object which is 'today' in this case.

Look at this one: we could have spent money, if we had some. He could have gone to England if he had studied well in school.

Could/would/might/may/etc are modals. We use the modal 'can' to make general statements about what is possible.

Example: It can be very cold in winter. (= It is sometimes very cold in winter) (Possibility)

We use 'could' as the past tense of can.

Example: It could be very cold in winter. (=Sometimes it was very cold in winter.) (Possibility)

We use could have to show that something is/was possible now or at some time in the past:

Example: It’s ten o’clock. They could have arrived now. (Possibility) They could have arrived hours ago. (Possibility)

'Now' and 'Today' are points in time, which you need to better understand the speaker/writer.

Answer 5

He could have been Prime Minister now if he hadn't decided to leave politics.

"Could have been" in this sentence uses the mood which indicates something under the hypothetical situation. This is not the mood to describe present, past nor future in the real world.

He could be Prime Minister now if he hadn't decided to leave politics.

"Could be" in this sentence also uses the mood showing something under the hypothetical situation. Therefore, the sentence is acceptable. The difference between "could have been" and "could be" is the possibility. When you think what you describe would never happen in the real world, people tend to use a past perfect form.

Wikipedia describes the definition of grammatical mood. http://en.wikipedia.org/wiki/Grammatical_mood

In linguistics, grammatical mood (sometimes mode) is a grammatical (and specifically, morphological) feature of verbs, used to signal modality.[1][2]:p.181;[3] That is, it is the use of verbal inflections—known as grammatical conjugation—that allow speakers to express their attitude toward what they are saying (for example, whether it is intended as a statement of fact, of desire, of command, etc.).