Which is correct –
He USED to go to the game on Friday.
He USE to go to the game on Friday.

When the statement is positive, as in the reader’s example, the expression is used to.

In negative statements, the expression is use to. For example, “He didn’t use to go to the game on Friday.”

The expressions are used to speak about things that were habitually done in the past. Both used and use are followed by an infinitive. For example:

We used to play baseball every Saturday.

I used to live in Cleveland.

There used to be a house on that corner.

The d is dropped when the sentence is negative:

I didn’t use to worry about money.

I didn’t use to celebrate Christmas.

There didn’t use to be a gas station on that corner.

Here are some current examples from the Web:

Chris Pratt Used To Live In A Scooby Doo Van

Pope Francis reveals he used to work as a bar bouncer

He [Jon Stewart] didn’t use to care and his show was funnier.

Actors didn’t use to be celebrities.

Women didn’t use to talk politics in this country.

I used to tell people we’d sell everything but the kitchen sink.

I used to love this view

Positive sentence: used to.
Negative sentence with didn’t: use to.

Courtesy: Daily Writing Tips