なぜなら

なぜなら
conjunction
because, the reason is
1. because, the reason is that
Used to introduce an explanation or reason for something stated before.
(かれ)()なかった。なぜなら病気(びょうき)だったからだ。
He didn't come. The reason is that he was sick.
Often followed by 〜からだ
なぜなら、(わたし)には時間(じかん)がないからです。
Because I don't have time.
成功(せいこう)した。なぜなら努力(どりょく)(つづ)けたからだ。
I succeeded, because I kept making an effort.
その計画(けいかく)には反対(はんたい)だ。なぜなら費用(ひよう)がかかりすぎるからだ。
I'm against that plan. The reason is that it costs too much.
彼女(かのじょ)信頼(しんらい)できる(ひと)だと(おも)う。なぜなら、いつも約束(やくそく)(まも)り、(こま)っている(ひと)(たす)けるからだ。
I think she is a trustworthy person. The reason is that she always keeps her promises and helps people in need.

USAGE:
なぜなら typically starts a new sentence or clause and is followed by the reason, often ending with からだ/からです.

PATTERN:
[Statement]. なぜなら〜からだ/からです。

SIMILAR EXPRESSIONS:

  • なぜなら (because, the reason is - formal/written)
  • だって (because - casual)
  • というのは (the reason is - explanatory)
  • というのも (the reason being - explanatory)

NOTE:
なぜなら is more common in written Japanese and formal speech. In casual conversation, だって or simply 〜から is more common.