# たとたん: as soon as; just when

> Learn how to use たとたん, a JLPT N3 Japanese grammar point meaning as soon as; just when, with structure, nuance, examples, mistakes, and comparisons.

JLPT level: N3 · Updated: 2026-05-17 · Canonical: https://hane-app.com/blog/n3-ta-totan/

**たとたん** means **as soon as; just when**. It is a **JLPT N3** grammar pattern used to **show that something happened immediately after another action**.

This grammar point often appears in **neutral** Japanese. If you want to **show that something happened immediately after another action**, **たとたん** is a useful pattern to learn.

## What does たとたん mean?

Use **たとたん** when you want to **show that something happened immediately after another action**.

Natural translations include:
- as soon as; just when
- as soon as
- as soon as / just when

## How to form たとたん

Verbた-form + とたん（に）

Examples of the pattern:
- 開けたとたん
- 着いたとたん
- 立ったとたん

## When is たとたん used?

Use **たとたん** in situations like:
- sudden events
- unexpected results
- immediate reactions

Tone and register:
- neutral
- Common in JLPT reading, grammar questions, and natural Japanese sentences

## たとたん example sentences

- 家を出たとたん、雨が降り始めた。 — As soon as I left the house, it started raining.
- ドアを開けたとたん、猫が飛び出した。 — The moment I opened the door, the cat jumped out.
- 駅に着いたとたん、電車が出発した。 — Just as I arrived at the station, the train departed.
- 薬を飲んだとたん、眠くなった。 — As soon as I took the medicine, I got sleepy.
- 立ち上がったとたん、めまいがした。 — As soon as I stood up, I felt dizzy.

## Nuance of たとたん

The key nuance is **immediacy, often with surprise or unexpected timing**.

This matters because **たとたん** does more than translate one English phrase. It shows how the speaker connects ideas, evaluates a situation, or frames the sentence for the listener.

For example:
- In context, it sounds natural when the surrounding sentence supports the nuance.
- Compared with **すぐに**, it has a different focus and level of formality.

## たとたん vs すぐに

Both **たとたん** and **すぐに** can appear in related situations, but they are different.

**たとたん**:
- means **as soon as; just when**
- fits the specific N3 pattern and nuance explained above

**すぐに**:
- すぐに simply means immediately; たとたん links two events with a sudden “the moment X happened” feel

Quick contrast examples:
- Target: 家を出たとたん、雨が降り始めた。 — As soon as I left the house, it started raining.
- Compare: Try replacing it with **すぐに** and check whether the nuance still matches.

## Common mistakes with たとたん

Watch out for these mistakes:
- Using it for planned actions by the same subject too freely
- Forgetting the past form before とたん
- Using it for gradual changes

## Is たとたん on the JLPT?

Yes. **たとたん** is commonly taught as **JLPT N3** grammar.

That means learners should be able to:
- recognize it in reading
- understand its nuance in context
- use it in simple original sentences

## Practice questions for たとたん

Try making your own sentences with these prompts:
- Say it rained as soon as you left.
- Say a cat jumped out when you opened a door.
- Say you got sleepy after medicine.

## Learning path for たとたん

To learn **たとたん** efficiently, review basic time connectors first, then focus on whether the action happens before, during, immediately after, or while something is still true.

1. First, make sure you can form **たとたん** without looking at the pattern chart.
2. Next, compare it with [上で（うえで）](/blog/n3-ue-de/), [たて](/blog/n3-tate/). These patterns are close enough that choosing between them helps you understand the nuance.
3. Finally, write short narratives where timing changes the meaning; then check whether replacing **たとたん** with [うちに](/blog/n3-uchi-ni/) changes the meaning.

## Related grammar to review next

- [上で（うえで）](/blog/n3-ue-de/) — because it helps you contrast timing, sequence, and “when” clauses.
- [たて](/blog/n3-tate/) — because it helps you contrast timing, sequence, and “when” clauses.
- [うちに](/blog/n3-uchi-ni/) — because it helps you contrast timing, sequence, and “when” clauses.
- [ところで](/blog/n3-tokoro-de/) — because it helps you contrast timing, sequence, and “when” clauses.

## Learn たとたん with Hane

If you want to review **たとたん** together with the related patterns above, Hane helps you connect grammar, kanji, and vocabulary in short, focused sessions.

Browse more lessons here:
- [All grammar lessons](/blog/)
- [JLPT N3 grammar lessons](/blog/n3/)