How to say "assure" in Japanese

• アシュア
  suru verbThis is simply the English word 'assure' taken into Japanese as a loanword. Being much less common, it is seldom the word you want for any sense of 'assure'; the native verb 請け合う is normally the better choice.
• 請け合ううけあうCommon
  godan verb, transitive verbCovers the core sense of 'assure': giving your word that something is true or will happen, with a nuance of personal guarantee or vouching. Typical when you confidently promise someone a result.
  私は彼かれの正直しょうじきを請け合うけあうことができない。↗

  I can't answer for his honesty.

For the core sense of 'assure'—giving a confident personal guarantee that something is true or will happen—use 「請け合う」; 「アシュア」 is merely the borrowed English word and is rarely the right choice.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• アシュアassure
• 請け合ううけあうto assure