Mike Reed
pfm Member
Aye is a noun, as is no - the ayes to the right the noes to the left; ha ha is not.
Yes and no are exclamations, though they can be used as nouns ('is that a yes, then?') A ha-ha is a ditch or made-made gulley (except in Thai, possibly). Could the affirmative in Thai be 'yes Siam?', I wonder.