ao short as a rule everywhere except in Arran and Kintyre where it is short e close. The same close e is heard in one or two instances such as adharc, fradharc, in Sutherland. In Foghar old Foghmhar ao is slightly obscured in some districts by a w coming from the old mh. Where ao is long it also becomes é in Arran and Kintyre. Elsewhere it is unchanged in most districts but occasionally becomes û. For example, û is found in aobhar and fòghlum in Sutherland and sometimes in East Perthshire, and is given by MacAlpine in aobrann (faobrann).
Foghlum has ò in MacAlpine and in Arran ‘fòlum’ but é in Kintyre.
In the other group of words which includes aodach, aodann, aog, aogasg, aotrom, ao, which again has become é in Arran and Kintyre, is more apt to become û outside of Argyllshire as in aodach, aodann, etc., in Skye, Perth, etc. Those words have sometimes been written with eu in lieu of ao as eudach, eudann, and eug seems to have been preferred to aog by Dr. MacBain. In North Argyll a distinction is attempted in regard to this word, aog being used for the noun (death) and eug for the verb. MacLeod and Dewar give eug as verb and noun, but aog only as a noun.
Aoi is generally the same as ao with i either forming a diphthong with it, or showing the ‘slender’ character of the following consonant. Aois for example is ‘és’ in Arran and Kintyre. A few irregularities occur here also. MacAlpine gives ûi (diphthong) for aoi in aoine as in Di-h-aoine and in naoi. The latter has ûi in North Argyll. Both have ì in Arran and Kintyre as has also maoin. Naoidhean has ì in Kintyre but seemingly short i in Arran. Maoidh is mì in Kintyre, mài in Arran, and mòidh with MacAlpine. Maois (Moses) and chaoidh or choidhche (ever) and also oidhche have ì in Arran and the first û, the others ûi, with MacAlpine. Caoin (weep) is cóin in East Perth and in Sutherland. In the latter county aoi often gets the sound of ì as in gaoith, MacAoidh (Mackay) and the parish name Claoin (Clyne).
As when a is changed to e, so also when ao is sounded é
