In Irish it's go síoraí / de shíor / go deo / go bráth / go brách /
In Irish it's "buanghrá"
Éire go brách/Éirinn go brách in Irish Scottish Gaelic: ?
In Irish it's "go Lá an Luain"
Caitlín go deo
Mo ghrá go deo
As adjective, Éireannach go deo. If a noun, Na Éireannaigh go deo (the Irish people forever).
mo cheannsa go deo
is linne go deo an bua
"Gaelic" can mean "Irish Gaelic' or "Scottish Gaelic". They are classified as two distinct languages.
http://wiki.answers.com/Q/What_is_the_Irish_Gaelic_for_%27forever_sisters%27"
Níl an tsíoraíocht fada go leor
Do chara go deo.