～途端（に）

• Reading: とたんに
• Romaji: totan ni
• Formation: Verb た-form + 途端（に）+ Unexpected/immediate result
• Kanji breakdown: 途: way, road; 端: edge, tip — together meaning the very edge or turning point of an action

Meaning

Expresses that something happened immediately the moment a preceding action was completed. Equivalent to 'the moment' or 'as soon as' in English.

This pattern emphasizes the immediacy and unexpectedness of a result that occurs right after an action is completed. The second event typically happens involuntarily or is surprising — the speaker did not plan for it. 途端に always follows the past tense (た-form) of a verb. Unlike たら, which simply states a condition, 途端に stresses the dramatic timing — something occurred at the very instant the first action finished. It is almost always used for events that actually happened, not hypothetical situations. The result is usually something the speaker could not control.

Examples

1. 外に出た途端に、激しい雨が降り始めた。 The moment I stepped outside, it started raining heavily.
2. 座った途端、椅子の脚が折れてしまった。 The moment I sat down, the chair leg broke.
3. 薬を飲んだ途端に、眠くなってきた。 The moment I took the medicine, I started feeling sleepy.

Usage Guide

Context: spoken, written, everyday

Tone: dramatic

Do Say

• 窓を開けた途端に、虫が飛び込んできた。
• 走り出した途端、足がもつれて転んだ。
• その知らせを聞いた途端に、涙が止まらなくなった。

Don't Say

• 明日起きる途端に、運動する。(Using 途端に with dictionary form — it requires た-form because it describes something that already happened) → 明日起きたら、運動する。
• 勉強した途端に、成績が上がった。(Using 途端に for a gradual result — studying does not produce instant grade improvement) → 勉強を続けたら、成績が上がった。

Origin & History

From the noun 途端 (totan), which originally meant 'the edge of the road' or a critical juncture. It evolved to mean a precise, pivotal moment when one thing transitions to another.

Cultural Context

Generation: All ages

Social background: Universal