How to express 'past perfect' in Japanse

There is a difference between the past form and the past perfect form, but it's easy.

I read this book.

わたしはこの本（ほん）を読（よ）んだ。

(watashiha kono honnwo yonnda)

I have read this book.

わたしはこの本を読んだことがある。

(watashiha kono honnwo yonndakotogaaru)

Just add ことがある to the end of a sentence.

That's all, maybe.