With regard to first names, are all first names lenited in the vocative case or are there some (depending on the first letter of the name possibly) that are not lenited? I've found a lot of information on lenition, but most of it pertains to surnames and not first names.

Thanks!

As far as I know (and someone will correct me if I am wrong), all first names beginning with consonants that take lenition are lenited. But not all consonants take lenition. Have a look here:

http://www.nualeargais.ie/gnag/lenition.htm

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Táim ag foghlaim Gaelainn na Mumhan

Tá fáilte roim nach aon cheartú!
I am a learner. Any translations offered are practice and should not be used unless confirmed.

All first names are lenited, except maybe some names borrowed from English.
Some examples for all letters that are used with Irish names:

A Aoife
A Bhreandáin
A Chonaill
A Dhónaill
A Eilís
A Fhearghail
A Ghearóidín
A Íosa
A Liam
A Mháire
A Nóra
A Órla
A Phádraig
A Rónáin
A Shéamais
A Thomáis
A Úna

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Is fearr Gaeilg na Gaeltaċta ná Gaeilg ar biṫ eile
Agus is í Gaeilg Ġaoṫ Doḃair is binne

GRMA!

Christy

A Chhristy

_________________
Táim ag foghlaim Gaelainn na Mumhan

Tá fáilte roim nach aon cheartú!
I am a learner. Any translations offered are practice and should not be used unless confirmed.

You guys are awesome. Not only do you provide great info, but also humor.

Ah no, in the Gaeltacht you hear a Mhichael, a Sharah, a Mhary etc

Not technically correct, though