a, ā, á, ǎ, à
exclamatory particle
Phonosemantic compound. 口 represents the meaning and 阿 represents the sound.
Definitions
a
exclamatory particle; modal particle ending sentence, showing affirmation, approval, or consent
ā
interjection of surprise; Ah!; Oh!
á
interjection expressing doubt or requiring answer; Eh?; what?
ǎ
interjection of surprise or doubt; My!; what's up?
à
interjection or grunt of agreement; uhm; Ah, OK; expression of recognition; Oh, it's you!
Sources