Monday’s lesson was about the patten “I wish you/people would …” and “I wish I could …”. Yesterday’s was about “I regret doing that. I wish I hadn’t done that” and “I regret not doing that. I wish I had done that”. I gave some textbook examples then elicited real-life examples from the students. Some time into the lesson, one student arrived late. I said “I wish you’d come on time”, then immediately thought “Oohh, I’ll have to talk to them about that”.
“I wish you’d come on time” is perfectly ambiguous between “I wish you would come on time” and “I wish you had come on time”. With most other main verbs, we can tell the difference, because would is followed by the base form of a verb, while had is followed by the past participle form. Taking a similar verb as an example, we can tell the difference between “I wish you’d arrive on time” (would) and “I wish you’d arrived on time” (had).
This ambiguity arises only when the base and past participle forms are the same, which is the case only with come, become and run; burst, cost, cut, hit, hurt, let, put, set and shut; and read (but only in writing, which I didn’t think about until I came to write the title of this blog; how did you interpret that?).
If I was talking to a student who was usually on time but wasn’t on this occasion, “I wish you’d come on time” would be inferred to mean “I wish you had come on time (today)”. But this student is habitually late (I think she comes directly from work), so there is no immediate way of telling the difference. Of course, I could always clearly say “I wish you would …” or “I wish you had …”.