In English, the "simple past" form of a verb can sometimes be used to convey irrealis meanings, without any preterite sense:
- If I was rich, I'd buy a Porsche.
- If you only knew!
- I wish I was there with you.
- I'd like to be able to say that he wrote brilliant poetry, but he doesn't.
- It's time you went to sleep.
I can think of several other languages that do this, including French ("si j'étais riche..."), Ancient Greek, and Modern Hebrew. In languages that have an aspect distinction, it seems to be specifically the imperfective past tense that does this.
- What is the specific set of irrealis contexts (e.g. counterfactual conditionals, etc.) in which past-tense forms can be used in English, and how does it differ from that of other languages that have this conflation? For example, in Hebrew, the conditional examples 1-3 above would be translated with a past-tense verb, but example 4 would need a present form and 5 a future.
- How widespread is this phenomenon? What other languages do this? Is it a European or Indo-European thing, or is it broader than that? (Hebrew is neither of these, of course, but Modern Hebrew got much of its syntax and idiom from European languages, so could have borrowed this.)
- What is the basis for this syncretism? Past and irrealis seem to have nothing in common; if anything, it would make more sense to line up past with realis and future with irrealis. Imperfective and irrealis maybe have a little more in common in that neither expresses a specific, single, real event, but this still doesn't seem like much. Given that this is a recurrent pattern across several languages, is there a cognitive reason for it?