1.
order, sequence, circumstances
The order of events or how things came about.
そういう次第です。
That's how things stand.
次第 = circumstances
事の次第を説明してください。
Please explain the circumstances of the matter.
ここに至った次第を詳しくお話しします。
I will explain in detail the circumstances that led to this.
2.
depending on
Used as a suffix meaning 'depending on' or 'up to'.
結果は努力次第だ。
The result depends on your effort.
〜次第 = depending on
天気次第で予定を変えます。
I'll change my plans depending on the weather.
合格できるかどうかは、あなたの頑張り次第です。
Whether you can pass or not depends on your efforts.
3.
as soon as
Used with verb stem to mean 'as soon as' or 'immediately upon'.
届き次第、ご連絡します。
I will contact you as soon as it arrives.
Verb stem + 次第 = as soon as
分かり次第お知らせします。
I will let you know as soon as I find out.
準備が終わり次第、出発しましょう。
Let's depart as soon as preparations are finished.
次第 has multiple uses as both a noun and suffix.
AS A NOUN:
- 事の次第 (circumstances, how things came about)
- 次第によっては (depending on circumstances)
AS A SUFFIX (〜次第):
- 天気次第 (depending on the weather)
- あなた次第 (up to you)
- 気持ち次第 (depends on how you feel)
WITH VERB STEM:
- 届き次第 (as soon as it arrives)
- 分かり次第 (as soon as I find out)
- 終わり次第 (as soon as it ends)
REGISTER: Somewhat formal, common in business and written Japanese.