WISH & IF

 WISH

1) To express a regret about the present, we use wish + the past simple :

•  I don't play the piano → I wish I played the piano.

2) To express a regret about the past, we use wish + the past perfect :

• - Julie lost her umbrella yesterday → Julie wishes she hadn't lost her umbrella.

3) To express a desire to change something, we use wish + the conditional (would):

• - The neighbours are making noise → I wish they would stop making noise.

IF

1) After if, we often use were instead of was, especially in a formal stylewhere it is considered more correct.

• - If I were rich, I would travel all over the world.
• - If he were a better manager, the company would be more successful.

2) We use the structure "if I were you ..." to give advice.

• - If I were you I would take English lessons.