啊

à
  1. interjection or grunt of agreement
  2. uhm
  3. Ah, OK
  4. expression of recognition
  5. Oh, it's you!

CEDICT

Homographs

啊 ā
  1. interjection of surprise
  2. Ah!
  3. Oh!
啊 á
  1. interjection expressing doubt or requiring answer
  2. Eh?
  3. what?
啊 ǎ
  1. interjection of surprise or doubt
  2. Eh?
  3. My!
  4. what's up?
啊 a modal particle ending sentence, showing affirmation, approval, or consent