約束します（やくそくします、yakusoくshimasu）
- to promise

The Japanese word 約束します (やくそくします) means "to promise," "to make a promise," or "to pledge." It signifies a commitment to do something or to ensure something will happen. The action of making a promise is the core meaning. The implication is often that the promise will be kept.

⚫︎明日、また電話をかけますと約束します。 Translation: I promise to call you again tomorrow. ⚫︎彼は必ず助けると約束しました。 Translation: He promised to help for sure. ⚫︎一生懸命勉強すると約束します。 Translation: I promise to study hard.

⚫︎You use 約束します when you want to formally or informally assure someone that you will do something or that something will happen. ⚫︎It's common to use it in everyday conversations, business settings, and formal situations. ⚫︎It implies a level of sincerity and intention to follow through. ⚫︎The verb often takes the particle と after the action that is being promised. ⚫︎For example: 約束します plus と plus action.

⚫︎This word is typically written as 約束します using the kanji 約束 and the hiragana します. ⚫︎約束 means "promise." ⚫︎します is the polite form of the verb する ("to do"). ⚫︎There is no other way to write this. The word does not change its okurigana (suffix hiragana). ⚫︎There can be a variations depending on the tense: ⚫︎約束する(やくそくする) - "to promise" (plain form) ⚫︎約束した(やくそくした) - "promised" (past tense, plain form) ⚫︎約束しますした(やくそくしました) - "promised" (past tense, polite form) ⚫︎約束します - "promise" (present/future tense, polite form)

⚫︎誓います(ちかいます) - "to swear," "to vow" (more formal and serious) ⚫︎約束する(やくそくする) - "to promise" (plain form, less polite) ⚫︎保証します(ほしょうします) - "to guarantee" ⚫︎承知しました(しょうちしました) - "I understand" / "I accept" (often used when agreeing to a promise or request)

⚫︎There isn't a direct antonym, but the opposite of keeping a promise would be breaking a promise. ⚫︎Breaking a promise doesn't have a single word, instead, you would describe it with phrases like: ⚫︎約束を破る(やくそくを破る) - "to break a promise" ⚫︎約束を違える(やくそくをたがえる) - "to go back on a promise"

私は、必ずあなたを助けると約束します。 ・Translation: I promise I will help you. ・Explanation: This sentence conveys a firm commitment to help someone.

試験に合格するために、毎日勉強すると約束します。 ・Translation: I promise to study every day to pass the exam. ・Explanation: The sentence expresses a commitment to studying regularly to achieve a goal.

⚫︎約束 is a compound word. ⚫︎約(yaku) means "to contract," "to promise," or "to abbreviate." ⚫︎束(soku) means "a bundle," "a tie," or "to bind." ⚫︎The combination implies a binding agreement or a tied promise. ⚫︎The verb する(suru) means "to do," so 約束します means "to make a promise," or "to do a promise."