Perfect Infinitives after Modals with NO Change of Time Reference

Perfect Infinitives after Modals with NO Change of Time Reference

Since this comment below

https://www.EnglishForward.com/English/WasSupposedReproachPast-Obligation/bllldr/post.htm

appears to have been a line too lengthy, I believe I should put the question in a more concise manner.

(The road to ignore zone was paved with good intentions - I was just trying to save the time for the kind responder to help pinpoint any flaws of my thinking.)

Please, verify my reasoning.

Premise1.

The perfect infinitive after modals (both in indicative and subjunctive) refers its action to the past (actually, to the prior period of time):

He should/needn't/'d better/'d rather have come yesterday. = I'd like him to have come yesterday.

Premise2.

However, as it seems, there're a few 'exceptions' to the rule above. In several expressions the perfect infinitive fails to definitively relate its action to the prior period of time:

1. He was to come. = He was to have come.

2. He was supposed to come. = He was supposed to have come.

3. He had to know. = He had to have known.

Which makes these sentences 'multipotential' and the perfect infinitive nothing more than an emphatic construction to stress the past aspect of the occurrence.

Hypothesis.

The reason why this perfect infinitive fails to do its regular job is the past form of the first verb of the predicate.

There's no 'pre-past' (pluperfect) for the perfect infinitive to relate its action to. And it refers it to the same time the predicate verb is.

That's why perfect infinitives are sort of redundant here and cannot convey any additional meaning compared to the non-perfect infinitive.

Proof (kinda).

The most obvious analogy of the way the perfect infinitive behaves after past modals would be another (false) opposition:

4. He was lucky to study at uni. = He was lucky to have studied at uni.

Since the facts of 'being lucky' and 'studying' refer to the same period of time, the perfect infinitive to have studied cannot relate its action to the pluperfect.

After all, it would make no sense to say:

He was lucky (yesterday) to have come (the day before yesterday).

Conclusion.

The perfect infinitive is unable to relate its action to the past the way it usually does after modals due to the past tense of the predicate verb, that's what makes the perfect infinitive just another decoration to underline the past character of the occurrence.

"... in a more concise manner" all right...

To anyone who would be patient enough to check all above, YETY would be infinitely obliged.

YETY