The Irish surname is Ó Dubhghaill but is sometimes modernized to Ó Dúghaill and Ó Dúill.
This form is used with male names, the female forms being different.
As a given name Dubhghall would be the spelling.
Mr. John Dougherty is Seán Ó Dochartaigh
Miss Mary Dougherty is Máire Ní Dhochartaigh
Mrs. Theresa Dougherty is Treasa Uí Dhochartaigh
Críostóir (male name)
O'Sullivan = Ó Súilleabháin
Niall is the Irish Gaelic form
The word for "name" is ainm in Irish (Gaelic);In (Scots) Gaelic it's also ainm.('Surname' is sloinne in Irish; sloinneadh in Scottish Gaelic.)
"Mac Toirdhealbhaigh" is the Irish Gaelic form.In a more modern spelling Mac Toiríolaigh.
It is an English name and most likely has no Irish Gaelic form.
No Irish equivalent.
'Melanie' is used in Ireland even with the surname in Gaelic. There is no Irish Gaelic version of the name.
The Scottish Gaelic form of the surname is MacIllFhionndaig.As a first name it would be Liondsaidh.(Some Irish families that adopted the name 'Lindsay' were MacClintock, Lynchy, and O'Lynn.)
You don't. It is not a Gaelic name.
The name for "Iceland" in Irish is "an Íoslainn"; The name in Scottish Gaelic: ?
The closest Gaelic name is Aidan, spelled Aodhán in Irish Gaelicand Aodhan in Scottish Gaelic.