10. "The poet translated the poem last year." The teacher said

В данном случае прямая речь стоит в прошедшем времени, а глагол главной части – в прошедшем, поэтому время в косвенной речи нужно изменить на Past Perfect.

The teacher said that the poet had translated the poem the year before.

Ответ: The teacher said that the poet had translated the poem the year before.