interjection:

• yes; that is correct - polite language
• understood; I see; OK; okay
• present; here - as a response to a roll call
• pardon?; what's that?; come again? - with rising intonation - colloquialism
• now; here; here you go - used when calling for someone's attention or when handing something to someone
• giddy-up; giddap

interjection / noun:

• Dear Sir or Madam, in reply to your letter ... - salutation of a formal letter of response

interjection:

• okay; sure; okey-dokey - colloquialism

interjection:

• yeah, yeah; sure - used for casual, half-hearted, or insincere agreement - colloquialism ➜ はい
• hey!
• hello ［はいはい］ - on phone, as a reply to もしもし
• giddy-up; gee-up; giddap ［はいはい］ - said to a horse ➜ はい

interjection:

• hello; hi - Ryūkyū dialect ➜ こんにちは

interjection / noun:

• respectfully yours - term used in closing a letter