たとたん

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）, たて. 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 changes the meaning.

Related grammar to review next

• 上で（うえで） — because it helps you contrast timing, sequence, and “when” clauses.
• たて — because it helps you contrast timing, sequence, and “when” clauses.
• うちに — because it helps you contrast timing, sequence, and “when” clauses.
• ところで — 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
• JLPT N3 grammar lessons