Translation guide
The English word 'need' can express necessity, requirement, or lack. In Japanese, it is expressed through various adjectives, verbs, and grammatical patterns depending on whether you are talking about something necessary, something you must do, or something lacking.
Expressing that something is necessary or required.
The most common and versatile word for 'need' or 'necessity'. Can be used as a noun or na-adjective.
Water is necessary to live.
I need more information.
A common verb meaning 'to be needed' or 'to be necessary'. Used for concrete things.
Pattern meaning 'need ~'. The thing needed is marked with が.
I need your help.
Expresses obligation or necessity to do something ('must', 'have to'). Often corresponds to 'need to'.
I need to get up early tomorrow.
Literally 'there is a need to ~'. More formal than 〜なくてはいけない.
We need to take measures immediately.
Expressing that something is lacking or desired.
Means 'not enough', 'insufficient'. Used when something is lacking in quantity.
Means 'want' or 'desire'. Can sometimes overlap with 'need' when expressing a strong desire for something necessary.
Means 'indispensable', 'essential'. Stronger than 必要.
He is indispensable to the team.
Expressing that someone must do something.
必要 is a na-adjective/noun meaning 'necessity' and can be used for abstract concepts. 要る is a verb meaning 'to be needed' and is typically used for concrete, tangible things. 必要 can also be used with がある to mean 'there is a need to do something'.
English 'need' is a verb, but Japanese often expresses it with adjectives (必要) or intransitive verbs (要る). Avoid directly translating 'I need X' as '私はXを必要する' — it's unnatural. Use 'Xが必要だ' or 'Xが要る' instead.
I need to think about it.
I need money.
Is experience needed for this job?
I need to do my homework.
新しいパソコンが欲しい。
I need a new computer. (lit. I want a new computer.)