when do we use "wish"??

Wish

Let's start off with the easy part. ' I wish to' can mean the same as 'I want to' but it is much, much more formal and much, much less common.

I wish to make a complaint.
You can also use 'wish' with a noun to 'offer good wishes'.

We wish you a Merry Christmas.
Notice that when you want to offer good wishes using a verb, you must use 'hope ' and not 'wish'

We wish you the best of luck.
We hope you have the best of luck.
However, the main use of 'wish' is to say that we would like things to be different from what they are, that we have regrets about the present situation.

I wish I was rich.(were in formal language)
He wishes he lived in Paris.
Notice that the verb tense which follows 'I wish' is 'more in the past' than the tense corresponding to its meaning.

I'm too fat. I wish I was/were thin.
I never get invited to parties. I wish I got invited to parties.
In the case of 'will' , where 'will' means 'show willingness' we use 'would'.

He won't help me. I wish he would help me.
You're making too much noise. I wish you would be quiet.
Where 'will' means a future event, we cannot use 'wish' and must use 'hope'.

There's a strike tomorrow. I hope some buses will still be running
In more formal English, we use the subjunctive form 'were' and not 'was' after 'wish'.

I wish I were taller.