Japanese grammar

What does ～しだい mean? Japanese grammar N2

～しだい means as soon as (A is finished, B immediately follows).

Quick facts
Level (estimated, JLPT framework)	N2
Structure	Vます (drop ます) + 次第 N (verbal noun) + 次第
Romaji	shidai
Meaning	as soon as (A is finished, B immediately follows)

Forming it

Noun	到着 + 次第
Verb	分かる → 分かり + 次第

How to use it

States that as soon as one thing is completed, the next thing is done immediately; somewhat formal style.

「～次第」 (attached to the masu-stem) expresses that IMMEDIATELY AFTER one thing is completed, the next thing is done right away: "as soon as… then…". More formal than 「たらすぐ」.
The second clause is usually a volitional future action of the speaker (will contact, will depart); the second clause does NOT use the past tense.
Different from 「次第で」 (depending on): 「次第」 (without で) means "as soon as".

Examples

結果(けっか)が分(わ)かり次第(しだい)、ご連絡(れんらく)します。
I will contact you as soon as the results are known.
準備(じゅんび)ができ次第(しだい)、出発(しゅっぱつ)しましょう。
Let’s depart as soon as the preparations are done.

Keep in mind

The following clause does not use the past tense (since it states something to be done right after).
Verbal nouns (到着, 完成) connect directly.

Common mistakes

Wrong家(いえ)に着(つ)き次第(しだい)、電話(でんわ)しました。

As soon as I get home, I will call right away.

Correct家(いえ)に着(つ)き次第(しだい)、電話(でんわ)します。

The clause after 「次第」 states something that will be done RIGHT AFTER; it does not use the past tense (します, not しました).
Wrong結果(けっか)が分(わ)かるしだい、連絡(れんらく)します。

As soon as I know the results, I will contact you.

Correct結果(けっか)が分(わ)かり次第(しだい)、連絡(れんらく)します。

「次第」 attaches to the MASU-STEM (分かり), not the dictionary form (分かる).

Exam tips

「次第」 = as soon as (masu-stem); the second clause is in the future, not the past.

Related patterns

All N2 grammar →