Present wishes indicate something that is “contrary to fact.” That is, wishes are
something that is untrue but desired. For example,
I wish that I had a sports car.
I wish that I were a doctor.
|(The truth is I don’t have a sports car.)
(I’m really not a doctor.)
For present wishes, the past tense is used in the that clause, because it indicates a situation that is only imagined. Sometimes the word that is omitted.
She wishes (that) she had a diamond ring.
He wishes (that) he were rich.
To express possibility (can) and future intention (will), use the modals could
She wishes that she could sing.
They wish that she would stop.
When a “be” verb is required, the word were
is used, regardless of the subject.
We wish you were here.
I wish (that) I were taller.