いずれにせよ

いずれにせよ
adverb
in any case; at any rate; anyway
1. in any case; at any rate; anyway; regardless
Formal expression for introducing a conclusion that holds regardless of circumstances.
いずれにせよ、明日(あした)までに()めなければならない。
In any case, we have to decide by tomorrow.
理由(りゆう)はどうあれ、いずれにせよ(あやま)るべきだ。
Whatever the reason, you should apologize anyway.
いずれにせよ、結果(けっか)来週(らいしゅう)()かる。
At any rate, we'll know the result next week.

いずれにせよ is a formal conjunction-like adverb used to introduce a conclusion that holds true regardless of the preceding circumstances. It typically appears at the beginning of a sentence.

REGISTER:
This is a written/formal expression, common in essays, news, speeches, and business communication. It sounds stiff in casual conversation.

VARIATIONS:

  • いずれにせよ: most formal
  • いずれにしても: formal, slightly softer
  • どちらにせよ: formal, implies choosing between two options
  • どちらにしても: somewhat formal, between two options

CASUAL EQUIVALENTS:

  • とにかく: anyway (general-purpose, casual)
  • ともかく: anyhow (casual, slightly literary)
  • どっちにしても: either way (casual spoken form)

GRAMMAR:
Followed by a statement of conclusion or decision. Often pairs with expressions of uncertainty or multiple possibilities in the preceding clause.