A usage that sets my teeth on edge has grown all too common among young people. An example:
I wish public schools would have taught English grammar better in the 1990s.
Surely this sentence should be,
I wish public schools had taught English grammar better in the 1990s.
Will someone please explain the rule covering this?
Grammatically, if you want to express a wish in the present, you use the simple past and to express a wish in the future, you use would + bare infinitive. In case of expressing a wish in the past, you mainly use had + past participle.
I wish he taught English grammar (expresses a wish in the present).
I wish he would teach English grammar (expresses a wish in the future).
I wish he had taught English grammar (expresses a wish in the past).
Some people also use would've to express a wish in the past in informal spoken English only as follows:
I wish he would have taught English grammar.
"Would have" is the conditional perfect, while "had" is the past perfect. https://www.grammarbook.com/newsletters/071012.htm The conditional is used is used when discussing something that would have resulted from a condition, e.g. "If had done better in high school, then I would have been accepted into a better college". The past perfect is used for things that were completed by some point in the past, or to express an irrealis mood: that is, something that is known to not happened. Basically, it's used to discuss an imaginary world where something different happened. For instance, in "If had done better in high school, then I would have been accepted into a better college", "had done better" is something that didn't happen, but I am discussing what I imagine would have happened in a universe where it did happen. In "I wish public schools had taught English grammar better in the 1990s", "had taught" refers to something that didn't happen, but I am discussing my preference for being in a universe where it did. So: "had" to introduce the universe, "would have" to discuss what would happen as a result of being in that universe: "I wish public schools had taught English grammar better in the 1990s; then all these people would have known the correct form to use."
And I don't think this is particular to young people.
This appears to be a mild form of overcorrection, where teens are taking a special case with "wish" and extending it into the past tense.
The following sentence is perfectly correct:
I wish public schools would teach English grammar better.
But this is a special case of "wish", where you're specifically talking about a wish that someone else would do something differently. It indicates that you're particularly irritated about a situation that's not under your control, but is under someone else's, and you're pretty sure they could change it if they wanted to.
Ordinarily, "wish" operates by (essentially) the same rules as backshifting:
I wish the schools taught English grammar better.
In this case, there's no particular implication that teaching better English is under the school's control. Out of context and without hearing the intonation, it's just a neutral statement: the speaker wants English grammar teaching to be better than it is.
It's therefore pretty clear where the mistake is occurring. The teen is thinking of the special case ("I wish schools would teach better") and backshifting it, instead of going back to the regular case ("I wish schools taught better") and backshifting that.
Now, there's no particular reason why the special case can't apply to the past, too. It's perfectly comprehensible to express the same concept in the past tense, that you think the schools could have taught better than they did. And this is probably what the kids are thinking when they use it this way. If we're approaching English descriptively, then it makes sense and would probably be understood by the average speaker. But approaching it prescriptively, it's not considered correct and should be avoided in formal speech or writing.
