Grammar Info
N3 Lesson 8: 13/22

第一(だいいち)
start, first (point), foremost, to begin with

Be careful when combining 第一 with chapter or section numbers (see Structure)

Structure
Casual
Formal
第一に + Phrase
第一 + + Noun
だいいっ + Noun (Chapter)
Phrase + 第一 +
第一に + Phrase
第一 + + Noun
だいいっ + Noun (Chapter・Section)
Phrase + 第一 + です
Details
Register Standard
使用域 一般
Information
第一(だいいち) is an expression in Japanese which may be used either as a 副詞(ふくし) (adverb), or as a 名詞(めいし) (noun). As a noun, it will carry the meaning of ‘foremost’, or ‘most important’. As an adverb, it can mean ‘first’, or ‘above anything’.
To use 第一(だいいち) adverbially, pair it with . As a noun, it will usually be followed by の (when connecting nouns), or by the 助動詞(じょどうし) (auxiliary verb) , when at the end of a sentence.
  • 第一(だいいち)彼(かれ)は何(なん)であんな時間(じかん)にここいたん
    First of all, why was he here at that time?
  • これここ第一(だいいち)ルール
    This is the number one rule here.
  • お金(かね)よりも健康(けんこう)でいること第一(だいいち)
    More than money, being healthy is the most important thing.
Occasionally, まず ‘first of all’ will be paired with 第一(だいいち). This may seem redundant, but is like saying ‘the very first’ in English.
  • まず第一(だいいち)この計画(けいかく)担当(たんとう)する人(ひと)決(き)めましょう
    Firstly, let's pick the person that will be in charge of this plan.
Fun Fact
第(だい) is a kanji that is often translated as ‘number’. However, the literal meaning is a bit closer to ‘position’, as it refers to the place that something has within a sequence of numbers. As such, 第一(だいいち) simply means ‘1st position’.
Slow Male
Hide All
Hide Japanese
Hide English
安全(あんぜん)は第一(だいいち)だ。
Safety first.
Play  
筋肉(きんにく)をつけたい場合(ばあい)は筋力(きんりょく)のトレーニングではなくてダイエット第一(だいいち)にするべきだ。
If you want to gain muscle, rather than training you should prioritize your diet.
Lit. 'make it first.' 'Start with'.
Play  
第一(だいいっ)節(せつ)第一(だいいっ)款(かん)検察官(けんさつかん)の義務(ぎむ)等(など)
Section 1, Subsection 1, Duties of public prosecutor, etc.
Play  
Online
Books
Tobira
Page 282