いたす

いたす is the humble (謙譲語) form of する ("to do"). It is used to lower the speaker's own actions in order to show respect toward the listener or the person being discussed. Because it is a humble form, it should only be used to describe your own actions (or those of your in-group), never the actions of someone you wish to honor.

Basic usage

いたす replaces する when speaking politely about what you yourself do. In polite speech, it is most common in its ます-form: いたします.

お／ご～いたす

いたす frequently appears in the pattern お + V[stem] + いたす or ご + 漢語名詞 + いたす, which is a humble way to describe performing an action for someone else's benefit.

する vs. いたす vs. なさる

Be careful not to confuse いたす with なさる. いたす is humble – used for your own actions. なさる is honorific (尊敬語) – used for someone else's actions.

Common set phrases

いたす appears in many fixed polite expressions:

• しつれい失礼いたします – "Excuse me" (when entering/leaving a room, ending a phone call, etc.)
• おねがいいたしますお願いいたします – "I humbly request" (polite way to ask for something)
• もうしわけ申し訳ございません。にど二度といたしません。 – "I'm terribly sorry. I won't do it again."