Abstract: A mechanical translation method includes a first step of dividing an input original sentence into a plurality of word trains in accordance with a predetermined division rule, a second step of converting the original sentence into a translated sentence for each divided word train, and a third step of displaying a pair of the original sentence and the translated sentence. In the first step, a predetermined symbol is inserted at partition positions of the divided original and translated sentences. In the third step, each word train of the divided original sentence and its corresponding translated sentence are displayed in a juxtaposed style. In the first step, the division operation is performed in accordance with a rule selected from a plurality of division rules. Also in the first step, the inserted symbol is different for each division rule.