Translation guide
The concept of something being necessary, unavoidable, or required. In Japanese, this is expressed through nouns, adjectives, and grammatical patterns that convey obligation, inevitability, or essential need.
Expressing that something is necessary or needed in a general sense.
The most common and versatile word for 'necessity' or 'need'. Can be used as a noun or na-adjective.
水は生きるために必要です。
Water is necessary for living.
もっと練習する必要がある。
There is a need to practice more.
Emphasizes the quality or degree of necessity. Often used in formal or analytical contexts.
この計画の必要性を説明してください。
Please explain the necessity of this plan.
Means 'indispensable' or 'essential'. Stronger than 必要, implying something cannot be done without.
酸素は生命に不可欠だ。
Oxygen is indispensable for life.
Expressing that someone must do something, or that an action is obligatory.
Standard pattern for 'must' or 'have to'. Used for both personal obligations and general rules.
明日までにレポートを出さなければならない。
I have to submit the report by tomorrow.
Slightly more colloquial than ～なければならない. Very common in spoken Japanese.
もう行かないといけない。
I have to go now.
Expresses 'should' based on moral duty, advice, or natural expectation. Softer than 'must'.
親の言うことを聞くべきだ。
You should listen to your parents.
Formal/literary pattern meaning 'cannot help but do' or 'have no choice but to'. Used for unavoidable actions.
事実を認めざるを得ない。
I have no choice but to accept the facts.
Expressing that something is inevitable or certain to occur.
Noun or na-adjective meaning 'inevitable' or 'necessary consequence'. Often used in logical or philosophical contexts.
失敗は成功への必然のステップだ。
Failure is an inevitable step toward success.
Expresses strong certainty or conviction that something is the case. 'Must be' or 'no doubt'.
彼は真実を知っているに違いない。
He must know the truth.
Indicates expectation based on reasoning. 'Should' or 'ought to' in the sense of logical necessity.
彼女はもう着いているはずだ。
She should have arrived by now.
Expressing that something is a necessary condition or requirement.
Means 'required' or 'mandatory'. Often used for items, conditions, or qualifications.
この仕事には経験が必須です。
Experience is required for this job.
Formal term for 'requirement' or 'necessary condition'. Used in business or legal contexts.
Expressing that something is not necessary or there is no need to do it.
Direct way to say 'there is no need to...'.
急ぐ必要はないよ。
There's no need to rush.
Casual and common way to say 'don't have to' or 'it's okay not to'.
無理に来なくてもいいよ。
You don't have to come if it's inconvenient.
必要 (necessary) is the general term. 不可欠 (indispensable) is stronger and often used for things absolutely essential.
水は必要だが、コーヒーは不可欠ではない。
Water is necessary, but coffee is not indispensable.
English 'necessity' can sometimes be translated directly as 必要性, but in many cases natural Japanese uses 必要 or a grammatical pattern like ～なければならない instead of a noun.
応募の要件を満たしていますか？
Do you meet the application requirements?