Is the "a" before "friend" to denote we're talking to someone?
Yes. And also for the same reason why caraid becomes charaid
I hope we will learn soon why there is an "h" in "charaid".
It's because caraid is in the vocative case here. When addressing someone directly, you use the vocative, so caraid becomes a charaid.
Why leat and not leibh
Leat is for adressing peers and younger people. It is also singular.
Leibh is for adressing older people & a group of people
Leibh is also seen as formal
If you are calling someone friend, you would be quite unlikely to use the formal.
Tapadh leibh agus beannachd, a charaid. ?
Tapadh leibh agus beannachd, a charaid. ?????
Why the "a" before mother, father, friend, et.
Is the softness at end of 'charaid' meant to sound like a soft-g? Also, does 'caraid' and the Welsh 'cariad' (dear, loved one) have the same ancestor?
Both would appear to come from words meaning 'to love' - caru in Welsh and caraid in Old Irish