意味
Something of significance or high value.
文化的背景
The phrase 'O-daiji ni' is used when someone is sick. It's a shortened version of 'Treat your body as an important matter.' In Japanese meetings, the 'important thing' is often saved for the end or introduced with 'Kekkyoku...' (In the end...). Japanese teachers use 'Daiji na koto' to signal that a specific point will be on the entrance exams (Juken). Influencers use '#{大事|だいじ}なこと' to share daily wisdom or life hacks with their followers.
The 'Na' Rule
Always remember that '{大事|だいじ}' is a na-adjective. If you forget the 'na', it sounds like 'Important thing' without the grammar connecting them.
Koto vs Mono
Don't use '{大事|だいじ}なこと' for your physical treasure. Use '{大事|だいじ}なもの' for your cat, your car, or your phone.
意味
Something of significance or high value.
The 'Na' Rule
Always remember that '{大事|だいじ}' is a na-adjective. If you forget the 'na', it sounds like 'Important thing' without the grammar connecting them.
Koto vs Mono
Don't use '{大事|だいじ}なこと' for your physical treasure. Use '{大事|だいじ}なもの' for your cat, your car, or your phone.
Sentence Starter
Start a sentence with '{大事|だいじ}なことは、...' to sound more authoritative and clear in your speech.
O-daiji ni
When you hear someone sneeze or say they are sick, just say 'O-daiji ni!' It's the most natural response.
自分をテスト
Fill in the missing particle.
{大事|だいじ} ( ) ことです。
'{大事|だいじ}' is a na-adjective, so it needs 'na' to connect to a noun.
Which sentence is most natural for 'Health is important'?
Choose the best option:
Health is an abstract concept, so '{こと|koto}' is the correct noun.
Complete the dialogue.
A: {仕事|しごと}で{何|なに}が{一番|いちばん}{大事|だいじ}ですか？ B: ( ) が{一番|いちばん}{大事|だいじ}なことだと{思|おも}います。
'{笑顔|えがお}' (smile) is a noun that fits the context of what is important at work.
Match the phrase to the situation.
When would you say '{大事|だいじ}なことを{忘|わす}れました'?
'Koto' refers to abstract things like information or tasks.
🎉 スコア： /4
ビジュアル学習ツール
Koto vs Mono
練習問題バンク
4 問題{大事|だいじ} ( ) ことです。
'{大事|だいじ}' is a na-adjective, so it needs 'na' to connect to a noun.
Choose the best option:
Health is an abstract concept, so '{こと|koto}' is the correct noun.
A: {仕事|しごと}で{何|なに}が{一番|いちばん}{大事|だいじ}ですか？ B: ( ) が{一番|いちばん}{大事|だいじ}なことだと{思|おも}います。
'{笑顔|えがお}' (smile) is a noun that fits the context of what is important at work.
When would you say '{大事|だいじ}なことを{忘|わす}れました'?
'Koto' refers to abstract things like information or tasks.
🎉 スコア： /4
よくある質問
10 問{大事|だいじ} is more objective (serious, important for a goal), while {大切|たいせつ} is more subjective (precious, emotionally valuable).
Yes, it means an 'important person,' usually in a functional or social sense (like a key client). For a loved one, '{大切|たいせつ}なひと' is more common.
Yes, but for very formal documents, '{重要|じゅうよう}な{事項|じこう}' (important items) is preferred.
Use '{一番|いちばん}{大事|だいじ}なこと' (Ichiban daiji na koto).
It's better to use '{秘密|ひみつ}' (himitsu) or '{大事|だいじ}な{話|はなし}' (an important talk).
It can be both, but in this phrase, it functions as a na-adjective.
It means 'Take care of yourself' or 'Get well soon.'
Yes, it means 'It's not an important thing' or 'It doesn't matter.'
'Koto' creates a noun phrase that refers to a specific matter or fact, which is more substantial than just using 'no'.
Yes, characters often use it before a big reveal or when discussing their 'way of the ninja' or values.
関連フレーズ
{大切|たいせつ}なこと
similarA precious/cherished thing
{重要|じゅうよう}なこと
specialized formAn important matter
{大事|だいじ}にする
builds onTo cherish or take care of
{肝心|かんじん}なこと
similarThe crucial point
{必要|ひつよう}なこと
similarA necessary thing
