是，是啊，當然。

Yes, yes, of course.

Source: Tatoeba

Sentence Composition

=1 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)
=1 是 shì variant of 是 shì
=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 啊 ā
  1. interjection of surprise
  2. Ah!
  3. Oh!
=3 啊 á
  1. interjection expressing doubt or requiring answer
  2. Eh?
  3. what?
=3 啊 ǎ
  1. interjection of surprise or doubt
  2. Eh?
  3. My!
  4. what's up?
=3 啊 à
  1. interjection or grunt of agreement
  2. uhm
  3. Ah, OK
  4. expression of recognition
  5. Oh, it's you!
=3 啊 a modal particle ending sentence, showing affirmation, approval, or consent
4 當然 dāngrán
  1. only natural
  2. as it should be
  3. certainly
  4. of course
  5. without doubt