o / a

Peerie function wirds ir wint tae be unstressed in maist languages, an very affen hae twa forms: a langer stressed een an a shorter unstressed een. In Shaetlan da unstressed version o Eng. 'of' is o, an da unstressed version o 'on' is a:

Wi a bit o luck we'll see dee a Setterdy.

Dis is neider new, nor slang, nor a døless wye o spaekkin. Hit wis started alreidy in Aald English: fae da 12C 'of' startit tae be reduced tae 'o' in unstessed plaesses, espeecially if da neest wird startit wi a consonant. Da preposition 'on' descends fae Proto-Germanic *ana an turnt intae an/on in Aald English. In unstressed plaesses it wis reduced ferder tae a, aless da neest wird startit wi a vowel. Dat's why it's still "ashore" (on+shore) athin Modren English.