I'm Alice Bryant.

The verb wish has a few uses in English.

One is to talk about regrets.

For example, I wish I had spent less time on social media last night.

When we use the phrase I wish I had to express regret.

We are saying we feel sorry that something was not different in the past.

For example, I said, I wish I had spent less time on social media last night.

Notice the word spent after the phrase I wish I had spent is the past participle of the verb spend.

Now listen, toe This speaker used the phrase and take note of the past participle that comes after I wish I had studied harder for the entrance exam.

Did you catch the past participle?

It was studied from the verb study.

Here's something worth mentioning about the phrase I wish I had.

Americans sometimes use less formal versions of it, such as the simple past tense like this.

I wish I studied harder for the entrance exam, and some Americans add the modal verb would to the phrase like this.

I wish I would have studied harder for the entrance exam.

Technically Neither of these is grammatically correct, but they are often considered acceptable in spoken English, and usually the meaning is clear, and that's everyday grammar.