“啊！”是一个感叹词。

"Ah!" is an interjection.

Source: Tatoeba

Sentence Composition

=1 啊 ā
  1. interjection of surprise
  2. Ah!
  3. Oh!
=1 啊 á
  1. interjection expressing doubt or requiring answer
  2. Eh?
  3. what?
=1 啊 ǎ
  1. interjection of surprise or doubt
  2. Eh?
  3. My!
  4. what's up?
=1 啊 à
  1. interjection or grunt of agreement
  2. uhm
  3. Ah, OK
  4. expression of recognition
  5. Oh, it's you!
=1 啊 a modal particle ending sentence, showing affirmation, approval, or consent
=2 是 shì
  1. to be (followed by substantives only)
  2. correct; right; true
  3. (respectful acknowledgement of a command) very well
  4. (adverb for emphatic assertion)
=2 是 shì variant of 是 shì
=3 一个 yīge
  1. a; an; one
  2. the whole (afternoon, summer vacation etc)
=3 一个 yīgè
  1. Combination of the numeral 一 (“one”) and the generic classifier 個／个: a; an; one
  2. same
4 感叹词 gǎntàncí
  1. interjection (part of speech)
  2. exclamation