He had written the book before he-

Complete sentence: He had written the book before he retired.

মনে রাখুন:

• Before দ্বারা যুক্ত দুটি clause-এর আগের অংশে Past perfect হলে পরের অংশে Past indefinite বসে। যেমন: We had reached the school before the ball rang.
• আগের অংশে Future perfect হলে পরের অংশে Present indefinite বসে। যেমন: We shall have reached the school before the bell rings.