YOU SAID:

They were the best of years, they were the worst of years.

INTO JAPANESE

彼らは年のベスト、彼らは最悪の年だった。

BACK INTO ENGLISH

They were at best, they are the worst year.

INTO JAPANESE

彼らは最高の状態でいた、彼らは最悪の年です。

BACK INTO ENGLISH

They are at best, they were the worst years.

INTO JAPANESE

彼らは最高の状態で、彼らは最悪の年だった。

BACK INTO ENGLISH

They are at best, they were the worst years.