Теория:

Studу the information about sentences with words "I wish" and "If only".

Words 'wish' and 'if only' are used to express a wish.

1. Use wish/ if only + past simple for the present when you want to say that we would like something to be different.
 
I wish/ if only I had a lot of friends. (But I don’t have a lot of friends.)
 
people-2567915_640.png
Рис. \(1\). Friends

2. Use wish/ if only + Past Perfect  when you want to express regret that something happened or did not happen in the past.
 
If only I had followed  your advice. (I did not follow it)
 
If I had come  to my relatives last week. (I did not come to my relatives)

3. Use wish/ if only or a polite imperative or when you want to express your wish for a change in a situation.
  
I wish she would put her things away.
 
I wish it would stop  snowing.
 
snowfall-201496_640.png
Рис. \(2\). Snowfall
After pronouns we and I use could instead of would.
I wish I could support  you.
Источники:
Рис. 1. Friends, 2017, https://pixabay.com/images/id-2567915/ Pixabay License CC0 Free for commercial use No attribution required
Рис. 2. Snowfall, 2013, https://pixabay.com/images/id-201496/ Pixabay License CC0 Free for commercial use No attribution required