Berlitz's substitute who spoke no English invented immersion teaching

In 1878 Maximilian Berlitz ran a small language school in Providence, Rhode Island, teaching in the conventional way of the era: grammar rules explained, vocabulary translated, sentences built by reference back to the student's native tongue at every step. It was the only method anyone taught by, and it was slow — every new word had to be filed under an equivalent word the student already owned, adding a translation step to every thought.

Berlitz fell seriously ill and had to hand his classes to a newly hired assistant, Nicholas Joly, a young Frenchman. Only after Joly had already started teaching did Berlitz discover the problem: Joly spoke no English at all, and could not have translated a single word even if the method had called for it.

With no shared language available, Joly taught entirely in French — gesturing, pointing, demonstrating, never once translating a word into English. When Berlitz returned six weeks later, he found his students spoke and understood far more French than any of his own translation-based classes had produced in the same time. He recognized the accident as the method: teach only in the target language from the first lesson, force the student to build meaning directly rather than through translation, and let context and repetition do the work grammar rules used to do.

Taught entirely in the target language with no translation, forcing direct meaning-building; the absent crutch proved the bottleneck and became the method.

No shared language forced direct associations between French and meaning, bypassing the slower translation step.

Students had no fallback, so they had to engage the skill immersion was meant to build.

The unplanned classroom result showed faster learning before any theory explained it.

When a standard method is slow because it lets people fall back on a familiar crutch, try removing the crutch instead of improving it.

Six weeks of zero-translation teaching outlearned grammar-translation classes; immersion became Berlitz's method worldwide. The direct/immersion method displaced grammar-translation as the dominant approach to language teaching worldwide and underlies most modern conversational-language pedagogy.