1
I wish I have a car.
I wish I had a car.
I wish I can swim, but I can’t.
I wish I could swim, but I can’t.
To talk about something you want to be different now, use a past form after wish: ‘I wish I had a car.’ Here, had refers to now, not the past. Use could, not can: ‘I wish I could swim.’
2
I wish I didn’t meet him yesterday at the party.
I wish I hadn’t met him yesterday at the party.
For a past regret, use the past perfect after wish: ‘I wish I hadn’t met him.’
3
I wish you have a pleasant stay.
I hope you have a pleasant stay.
I wish you a pleasant stay.
I wish you will come back soon.
I hope you will come back soon.
Use hope to say that you want something to happen in the future: ‘I hope you have a pleasant stay.’ We can also use wish + person + noun to send good wishes: ‘I wish you a pleasant stay.’
Do not use wish + present or will for this meaning.
Check our grammar lesson on the difference between wish, hope and expect.
See HOPE