Translation guide
A modal expression used to give advice, express obligation, or state what is likely or expected. In Japanese, this is expressed through various grammar patterns and phrases rather than a single word.
To suggest that someone should do something because it is a good idea or the right thing to do.
A common and natural way to give advice. Literally means 'it is better to do ~'. Attach to the past tense plain form of a verb.
もっと早く寝たほうがいいよ。
You ought to go to bed earlier.
You ought to see a doctor.
Expresses a strong sense of moral obligation or duty. More formal and forceful than 〜たほうがいい. Attach to the dictionary form of a verb.
約束は守るべきだ。
You ought to keep your promises.
もっと勉強するべきだと思う。
I think you ought to study more.
A casual, shortened form of 〜ないといけない (must do). Often used in spoken Japanese to imply 'ought to' or 'had better'. Attach to the negative stem of a verb.
そろそろ行かないと。
I ought to get going soon.
ちゃんと食べないと。
You ought to eat properly.
To indicate that something is required or expected, often due to rules, morality, or social norms.
A formal expression meaning 'must' or 'have to'. It conveys a strong sense of obligation. Attach to the negative stem of a verb.
税金を払わなければならない。
You ought to pay your taxes.
規則に従わなければならない。
You ought to follow the rules.
Also used for moral obligation. See above for details.
親の言うことを聞くべきだ。
You ought to listen to your parents.
A slightly less formal version of 〜なければならない, common in everyday speech. Attach to the negative stem of a verb.
明日までにレポートを出さないといけない。
I ought to submit the report by tomorrow.
To say that something is probable or expected to happen based on evidence or reasoning.
Indicates that the speaker expects something to be true based on logical reasoning. Attach to the dictionary form of verbs and adjectives.
彼はもう着いているはずだ。
He ought to have arrived by now.
この薬を飲めば、よくなるはずだ。
If you take this medicine, you ought to get better.
Used to express a natural conclusion or expectation. Similar to 'it follows that' or 'ought to' in a logical sense.
毎日練習すれば、上手になるわけだ。
If you practice every day, you ought to improve.
Expresses strong conviction that something is true. More emphatic than はずだ. Attach to dictionary form.
彼は成功するに違いない。
He ought to succeed.
〜たほうがいい is a softer, more practical suggestion ('it would be better to...'), while 〜べきだ carries a stronger moral or logical imperative ('one ought to...'). Use 〜たほうがいい for everyday advice and 〜べきだ for serious obligations or general principles.
傘を持っていったほうがいいよ。
You ought to take an umbrella (it might rain).
人は正直であるべきだ。
People ought to be honest.
There is no single Japanese word that directly corresponds to 'ought to'. Using a dictionary translation like 当然 (touzen) or 義務 (gimu) will not work in sentences. Always use a grammar pattern as shown above.