Complex sentence: MacDonald, Macdonald, and McDonald are Anglicised forms of the Scottish Gaelic and Irish Gaelic "MacDhòmhnaill" or "Dòmhnallach".
Split into simpler sentences: MacDonald, Macdonald, and McDonald are Scottish and Irish surnames. These surnames are Anglicised forms of the Scottish Gaelic and Irish Gaelic "MacDhòmhnaill" or "Dòmhnallach".