Bidirectional Translation

Bidirectional translation is a single exercise repeated on a cycle. You take a short text you can nearly understand — a dialogue from a course, a paragraph from a graded reader — and translate it into your native language, carefully, so the result reads naturally. You leave it a few days. Then you translate your native-language version back into the target language without looking at the original, and finally you compare the two, line by line.

The comparison is the whole point. Everywhere your reconstruction differs from the original is a precise, personal diagnosis: a preposition you guessed, a tense you avoided, a word order you imported from your own language, an idiom you paraphrased because you did not have it. Unlike a textbook exercise, the gaps found are yours, and unlike free writing, there is a correct version sitting right there to check against.

The Italian polyglot Luca Lampariello is the person most associated with the technique today; he describes it as the backbone of how he has learned a dozen or more languages, and teaches it as a three-step cycle. But the underlying exercise is old. Assimil's 'active wave' — going back to lesson one and rendering the native-language page into the target language — is exactly this, built into a course from 1929. Older still, Roger Ascham's The Scholemaster of 1570 advocated 'double translation' of a model text, a technique he himself noted was not new.

A working session is twenty to forty minutes, a few times a week, on texts of five to fifteen lines with audio. It suits roughly A2 upwards: below that there is not enough language to reconstruct anything, and the exercise collapses into guessing.

It is unfashionable, because translation carries the smell of the classroom method it is nothing like. The difference is direction and purpose: grammar-translation used translation to test rules on sentences invented for the purpose, while this uses it to find and close your own gaps on natural text you want to be able to produce.