Tom here, from BBC Learning English in London.

And today, I'm gonna tell you what to say after the word wish.

When we're talking about wishes, we're talking about situations that are imaginary or unreal.

To show this, after saying 'I wish', we use the past to talk about the wish, which is in the present.

So, I could say:

I wish I had a cup of tea.

Ah, thank you!

Now, if we want to make a wish about the past, we need to use the 'past past' or the past perfect.

For example:

I wish I had chosen a more formal shirt before I filmed this video today.