Translation guide
Expressing that something is essential or indispensable. Japanese uses various patterns depending on whether you mean 'can't live without', 'can't manage without', or 'absolutely necessary'.
To say that you cannot live or function without something (e.g., coffee, phone, a person).
Literally 'cannot be without'. Used for things you feel you must have, often emotionally or habitually.
コーヒーなしではいられない。
I can't do without coffee.
Means 'must have' or 'indispensable'. Slightly more formal than なしではいられない.
スマホは今や生活になくてはならないものだ。
Smartphones are now something we cannot do without in daily life.
Implies that without something, you cannot get by or it won't be acceptable. Stronger nuance of necessity.
この書類なしでは済まない。
We can't do without this document.
To say that something is necessary to accomplish a specific goal or handle a situation.
Literally 'if I don't have it, I'll be troubled'. Common for everyday needs.
辞書がなくては困る。
I can't do without a dictionary.
Casual version of なくては困る. Used in spoken Japanese.
スマホがないと困るよ。
I can't do without my smartphone.
Formal expression meaning 'absolutely necessary'. Used in writing or formal speech.
このプロジェクトには彼の協力が必要不可欠だ。
His cooperation is something we cannot do without for this project.
To express that someone is indispensable, often in emotional or practical terms.
Dramatic expression meaning 'cannot live without'. Used for romantic or deeply dependent relationships.
あなたなしでは生きていけない。
I can't live without you.
Means 'an indispensable presence'. More formal and less emotional.
彼はチームになくてはならない存在だ。
He is someone the team cannot do without.
Both mean 'without', but なしでは often implies a habitual or emotional inability to be without, while なくては is more about practical necessity. なしでは is slightly more literary.
音楽なしではいられない。
I can't be without music.
パスポートがなくては海外に行けない。
I can't go abroad without a passport.
Do not directly translate 'cannot do without' as できない without. The natural Japanese expressions use なしでは or なくては patterns.