1 I wish you HAD COME / CAME to the exhibition yesterday! 2. If only I COULD design something like that! 3.I wish I COULD THINK of a new design that was so useful and so popular! 4.I wish I COULD REMEMBER that designer's name, but I've forgotten for the moment! 5.If only you DID NOT / DIDN'T oversleep and miss the bus!

Tania, piénsalo así ... si es subjuntivo del pasado en español (como 'pudiera', o 'hubiera'), entonces se forma como el pasado simple de inglés. Por ejemplo, 'Ojalá que pudiera diseñar algo así' = 'I wish I could design something like that'. O, 'Quiero que hubieras venido ayer' = 'I wish you had come yesterday'. O sea, en inglés usamos el pasado simple también para subjuntivo del pasado.

1. had come 2. could 3. could think 4. could remember 5. didn't

- I wish you had come/could come______ (can come) to the exhibition yesterday! - If only I _could_design______ (can design) something like that! - I wish I _could think_______ (can think) of a new design that was so useful and so popular! - I wish I could remember________ (can remember) the designer's name, but I've forgotten for the moment! - If only you _had not overslept/did not_oversleep____ (not oversleep) and missed the bus If you are refering to a past event that cant be changed or to wish, you use the past tense , not actually refering to a past action , but , the other meaning , that is its impoossble for the action to be done when you are saying it See my answer to 'wish vs hope' in my profile page for details

The first one could also be: I wish you could have come to the exhibition yesterday!