Translation guide
The English word 'as' has many grammatical roles. This guide covers the most common uses for learners: comparisons, roles/functions, simultaneous actions, reasons, and set phrases. Japanese does not have a single word that covers all uses of 'as', so you must choose the right pattern based on the meaning.
Expressing that two things are equal in some quality.
Use this pattern to say 'A is as C as B'. C is an adjective or adverb.
彼は私と同じくらい背が高い。
He is as tall as me.
Used in negative sentences to mean 'A is not as C as B'. In positive sentences, it can mean 'A is as C as B', but 同じくらい is more common for positive equality.
今日は昨日ほど暑くない。
Today is not as hot as yesterday.
For nouns, use 同じ to say 'A is the same as B'.
この車はあの車と同じだ。
This car is the same as that car.
Indicating the role, capacity, or function of someone or something.
Attach to a noun to mean 'as (a) ...'. It marks the role or capacity.
彼は医者として働いている。
He works as a doctor.
趣味として日本語を勉強しています。
I study Japanese as a hobby.
A simpler particle that can sometimes replace として, especially in casual speech, but として is clearer for roles.
お礼の気持ちでこれを作りました。
I made this as a token of gratitude.
Describing two actions happening at the same time, or one action happening while another is in progress.
Attach to the stem of a verb to mean 'while doing'. The subject must be the same for both actions.
音楽を聴きながら勉強した。
I studied as I listened to music.
Means 'while' or 'during the time when'. Often used when the first action provides an opportunity for the second.
若いうちに旅行したい。
I want to travel while I'm young.
Means 'at the same time as'. More formal or written.
彼が入ると同時に会議が始まった。
The meeting started as he entered.
Giving a reason or cause, often in formal or written contexts.
A common way to give a reason. Softer and more explanatory than から.
雨が降っているので、試合は中止です。
As it is raining, the game is canceled.
Formal, often used in written Japanese. Can also mean 'for the purpose of'.
事故のため、電車が遅れています。
As a result of an accident, the train is delayed.
Describing the way something is done or happens.
Means 'in the way that' or 'like'. Used after verbs and adjectives.
私が言うようにやってください。
Do as I say.
Means 'exactly as' or 'in accordance with'. Often used with nouns like 指示 (instructions) or 予定 (plan).
説明書のとおりに組み立てた。
I assembled it as per the instructions.
Common expressions where 'as' is part of a fixed phrase.
In Japanese, use できるだけ早く.
できるだけ早く返事をください。
Please reply as soon as possible.
Commonly translated as いつもどおり or 相変わらず.
彼はいつもどおり遅刻した。
He was late as usual.
Use the topic marker は to mean 'as for' or 'speaking of'.
私は、その意見に反対です。
As for me, I disagree with that opinion.
There is no single Japanese word that covers all uses of 'as'. Always identify the meaning first (comparison, role, reason, etc.) and use the appropriate pattern. Direct translation often leads to unnatural Japanese.
ので is softer and more objective, often used for explanations. から is more subjective and can sound like an excuse. In formal writing, ため is common.